[5408] | 1 | MODULE lmdz_lscp_precip |
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| 2 | !---------------------------------------------------------------- |
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| 3 | ! Module for the process-oriented treament of precipitation |
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| 4 | ! that are called in LSCP |
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| 5 | ! Authors: Atelier Nuage (G. Riviere, L. Raillard, M. Wimmer, |
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| 6 | ! N. Dutrievoz, E. Vignon, A. Borella, et al.) |
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| 7 | ! Jan. 2024 |
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| 8 | |
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| 9 | |
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| 10 | IMPLICIT NONE |
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| 11 | |
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| 12 | CONTAINS |
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| 13 | |
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| 14 | !---------------------------------------------------------------- |
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| 15 | ! historical (till CMIP6) version of the pre-cloud formation |
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| 16 | ! precipitation scheme containing precip evaporation and melting |
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| 17 | |
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| 18 | SUBROUTINE histprecip_precld( & |
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| 19 | klon, dtime, iftop, paprsdn, paprsup, pplay, zt, ztupnew, zq, & |
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[5411] | 20 | zmqc, zneb, znebprecip, znebprecipclr, & |
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[5408] | 21 | zrfl, zrflclr, zrflcld, zifl, ziflclr, ziflcld, dqreva, dqssub & |
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| 22 | ) |
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| 23 | |
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| 24 | USE lmdz_lscp_ini, ONLY : iflag_evap_prec |
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| 25 | USE lmdz_lscp_ini, ONLY : coef_eva, coef_sub, ztfondue |
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| 26 | USE lmdz_lscp_ini, ONLY : RCPD, RLSTT, RLVTT, RLMLT, RVTMP2, RTT, RD, RG |
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| 27 | USE lmdz_lscp_tools, ONLY : calc_qsat_ecmwf |
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| 28 | |
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| 29 | IMPLICIT NONE |
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| 30 | |
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| 31 | |
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| 32 | INTEGER, INTENT(IN) :: klon !--number of horizontal grid points [-] |
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| 33 | REAL, INTENT(IN) :: dtime !--time step [s] |
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| 34 | LOGICAL, INTENT(IN) :: iftop !--if top of the column |
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| 35 | |
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| 36 | |
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| 37 | REAL, INTENT(IN), DIMENSION(klon) :: paprsdn !--pressure at the bottom interface of the layer [Pa] |
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| 38 | REAL, INTENT(IN), DIMENSION(klon) :: paprsup !--pressure at the top interface of the layer [Pa] |
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| 39 | REAL, INTENT(IN), DIMENSION(klon) :: pplay !--pressure in the middle of the layer [Pa] |
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| 40 | |
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| 41 | REAL, INTENT(INOUT), DIMENSION(klon) :: zt !--current temperature [K] |
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| 42 | REAL, INTENT(IN), DIMENSION(klon) :: ztupnew !--updated temperature of the overlying layer [K] |
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| 43 | |
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| 44 | REAL, INTENT(INOUT), DIMENSION(klon) :: zq !--current water vapor specific humidity (includes evaporated qi and ql) [kg/kg] |
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| 45 | REAL, INTENT(INOUT), DIMENSION(klon) :: zmqc !--specific humidity in the precipitation falling from the upper layer [kg/kg] |
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| 46 | |
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| 47 | REAL, INTENT(IN), DIMENSION(klon) :: zneb !--cloud fraction IN THE LAYER ABOVE [-] |
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[5411] | 48 | REAL, INTENT(INOUT), DIMENSION(klon) :: znebprecip !--fraction of precipitation IN THE LAYER ABOVE [-] |
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[5408] | 49 | REAL, INTENT(INOUT), DIMENSION(klon) :: znebprecipclr !--fraction of precipitation in the clear sky IN THE LAYER ABOVE [-] |
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| 50 | |
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| 51 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrfl !--flux of rain gridbox-mean coming from the layer above [kg/s/m2] |
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| 52 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrflclr !--flux of rain gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
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| 53 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrflcld !--flux of rain gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
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| 54 | REAL, INTENT(INOUT), DIMENSION(klon) :: zifl !--flux of snow gridbox-mean coming from the layer above [kg/s/m2] |
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| 55 | REAL, INTENT(INOUT), DIMENSION(klon) :: ziflclr !--flux of snow gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
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| 56 | REAL, INTENT(INOUT), DIMENSION(klon) :: ziflcld !--flux of snow gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
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| 57 | |
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| 58 | REAL, INTENT(OUT), DIMENSION(klon) :: dqreva !--rain tendency due to evaporation [kg/kg/s] |
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| 59 | REAL, INTENT(OUT), DIMENSION(klon) :: dqssub !--snow tendency due to sublimation [kg/kg/s] |
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| 60 | |
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| 61 | |
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| 62 | REAL :: zmair |
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| 63 | REAL :: zcpair, zcpeau |
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| 64 | REAL, DIMENSION(klon) :: qzero |
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| 65 | REAL, DIMENSION(klon) :: zqs, zdqs |
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| 66 | REAL, DIMENSION(klon) :: qsl, qsi |
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| 67 | REAL, DIMENSION(klon) :: dqsl, dqsi |
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| 68 | |
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| 69 | REAL :: zqev0 |
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| 70 | REAL :: zqev, zqevt |
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| 71 | REAL :: zqevi, zqevti |
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| 72 | |
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| 73 | REAL, DIMENSION(klon) :: zrfln, zifln |
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| 74 | |
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| 75 | REAL :: zmelt |
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| 76 | INTEGER :: i |
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| 77 | |
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| 78 | qzero(:) = 0. |
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| 79 | |
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| 80 | |
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| 81 | ! -------------------------------------------------------------------- |
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| 82 | ! P1> Thermalization of precipitation falling from the overlying layer |
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| 83 | ! -------------------------------------------------------------------- |
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| 84 | ! Computes air temperature variation due to enthalpy transported by |
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| 85 | ! precipitation. Precipitation is then thermalized with the air in the |
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| 86 | ! layer. |
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| 87 | ! The precipitation should remain thermalized throughout the different |
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| 88 | ! thermodynamical transformations. |
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| 89 | ! The corresponding water mass should |
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| 90 | ! be added when calculating the layer's enthalpy change with |
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| 91 | ! temperature |
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| 92 | ! --------------------------------------------------------------------- |
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| 93 | |
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| 94 | IF (iftop) THEN |
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| 95 | |
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| 96 | DO i = 1, klon |
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| 97 | zmqc(i) = 0. |
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| 98 | ENDDO |
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| 99 | |
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| 100 | ELSE |
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| 101 | |
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| 102 | DO i = 1, klon |
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| 103 | |
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| 104 | zmair=(paprsdn(i)-paprsup(i))/RG |
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| 105 | ! no condensed water so cp=cp(vapor+dry air) |
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| 106 | ! RVTMP2=rcpv/rcpd-1 |
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| 107 | zcpair=RCPD*(1.0+RVTMP2*zq(i)) |
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| 108 | zcpeau=RCPD*RVTMP2 |
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| 109 | |
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| 110 | ! zmqc: precipitation mass that has to be thermalized with |
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| 111 | ! layer's air so that precipitation at the ground has the |
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| 112 | ! same temperature as the lowermost layer |
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| 113 | zmqc(i) = (zrfl(i)+zifl(i))*dtime/zmair |
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| 114 | ! t(i,k+1)+d_t(i,k+1): new temperature of the overlying layer |
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| 115 | zt(i) = ( ztupnew(i)*zmqc(i)*zcpeau + zcpair*zt(i) ) & |
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| 116 | / (zcpair + zmqc(i)*zcpeau) |
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| 117 | |
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| 118 | ENDDO |
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| 119 | |
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| 120 | ENDIF |
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| 121 | |
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| 122 | ! -------------------------------------------------------------------- |
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| 123 | ! P2> Precipitation evaporation/sublimation/melting |
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| 124 | ! -------------------------------------------------------------------- |
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| 125 | ! A part of the precipitation coming from above is evaporated/sublimated/melted. |
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| 126 | ! -------------------------------------------------------------------- |
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| 127 | |
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| 128 | IF (iflag_evap_prec.GE.1) THEN |
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| 129 | |
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| 130 | ! Calculation of saturation specific humidity |
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| 131 | ! depending on temperature: |
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| 132 | CALL calc_qsat_ecmwf(klon,zt,qzero,pplay(:),RTT,0,.false.,zqs,zdqs) |
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| 133 | ! wrt liquid water |
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| 134 | CALL calc_qsat_ecmwf(klon,zt,qzero,pplay(:),RTT,1,.false.,qsl,dqsl) |
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| 135 | ! wrt ice |
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| 136 | CALL calc_qsat_ecmwf(klon,zt,qzero,pplay(:),RTT,2,.false.,qsi,dqsi) |
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| 137 | |
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| 138 | DO i = 1, klon |
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| 139 | |
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| 140 | ! if precipitation |
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| 141 | IF (zrfl(i)+zifl(i).GT.0.) THEN |
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| 142 | |
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| 143 | ! LudoTP: we only account for precipitation evaporation in the clear-sky (iflag_evap_prec>=4). |
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| 144 | ! c_iso: likely important to distinguish cs from neb isotope precipitation |
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| 145 | |
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| 146 | IF (iflag_evap_prec.GE.4) THEN |
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| 147 | zrfl(i) = zrflclr(i) |
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| 148 | zifl(i) = ziflclr(i) |
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| 149 | ENDIF |
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| 150 | |
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| 151 | IF (iflag_evap_prec.EQ.1) THEN |
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| 152 | znebprecip(i)=zneb(i) |
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| 153 | ELSE |
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| 154 | znebprecip(i)=MAX(zneb(i),znebprecip(i)) |
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| 155 | ENDIF |
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| 156 | |
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| 157 | IF (iflag_evap_prec.GT.4) THEN |
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| 158 | ! Max evaporation not to saturate the clear sky precip fraction |
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| 159 | ! i.e. the fraction where evaporation occurs |
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| 160 | zqev0 = MAX(0.0, (zqs(i)-zq(i))*znebprecipclr(i)) |
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| 161 | ELSEIF (iflag_evap_prec .EQ. 4) THEN |
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| 162 | ! Max evaporation not to saturate the whole mesh |
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| 163 | ! Pay attention -> lead to unrealistic and excessive evaporation |
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| 164 | zqev0 = MAX(0.0, zqs(i)-zq(i)) |
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| 165 | ELSE |
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| 166 | ! Max evap not to saturate the fraction below the cloud |
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| 167 | zqev0 = MAX(0.0, (zqs(i)-zq(i))*znebprecip(i)) |
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| 168 | ENDIF |
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| 169 | |
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| 170 | ! Evaporation of liquid precipitation coming from above |
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| 171 | ! dP/dz=beta*(1-q/qsat)*sqrt(P) |
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| 172 | ! formula from Sundquist 1988, Klemp & Wilhemson 1978 |
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| 173 | ! LTP: evaporation only in the clear sky part (iflag_evap_prec>=4) |
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| 174 | |
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| 175 | IF (iflag_evap_prec.EQ.3) THEN |
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| 176 | zqevt = znebprecip(i)*coef_eva*(1.0-zq(i)/qsl(i)) & |
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| 177 | *SQRT(zrfl(i)/max(1.e-4,znebprecip(i))) & |
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| 178 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 179 | ELSE IF (iflag_evap_prec.GE.4) THEN |
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| 180 | zqevt = znebprecipclr(i)*coef_eva*(1.0-zq(i)/qsl(i)) & |
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| 181 | *SQRT(zrfl(i)/max(1.e-8,znebprecipclr(i))) & |
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| 182 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 183 | ELSE |
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| 184 | zqevt = 1.*coef_eva*(1.0-zq(i)/qsl(i))*SQRT(zrfl(i)) & |
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| 185 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 186 | ENDIF |
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| 187 | |
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| 188 | zqevt = MAX(0.0,MIN(zqevt,zrfl(i))) * RG*dtime/(paprsdn(i)-paprsup(i)) |
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| 189 | |
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| 190 | ! sublimation of the solid precipitation coming from above |
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| 191 | IF (iflag_evap_prec.EQ.3) THEN |
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| 192 | zqevti = znebprecip(i)*coef_sub*(1.0-zq(i)/qsi(i)) & |
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| 193 | *SQRT(zifl(i)/max(1.e-4,znebprecip(i))) & |
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| 194 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 195 | ELSE IF (iflag_evap_prec.GE.4) THEN |
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| 196 | zqevti = znebprecipclr(i)*coef_sub*(1.0-zq(i)/qsi(i)) & |
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| 197 | *SQRT(zifl(i)/max(1.e-8,znebprecipclr(i))) & |
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| 198 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 199 | ELSE |
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| 200 | zqevti = 1.*coef_sub*(1.0-zq(i)/qsi(i))*SQRT(zifl(i)) & |
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| 201 | *(paprsdn(i)-paprsup(i))/pplay(i)*zt(i)*RD/RG |
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| 202 | ENDIF |
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| 203 | |
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| 204 | zqevti = MAX(0.0,MIN(zqevti,zifl(i))) * RG*dtime/(paprsdn(i)-paprsup(i)) |
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| 205 | |
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| 206 | ! A. JAM |
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| 207 | ! Evaporation limit: we ensure that the layer's fraction below |
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| 208 | ! the cloud or the whole mesh (depending on iflag_evap_prec) |
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| 209 | ! does not reach saturation. In this case, we |
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| 210 | ! redistribute zqev0 conserving the ratio liquid/ice |
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| 211 | |
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| 212 | IF (zqevt+zqevti.GT.zqev0) THEN |
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| 213 | zqev=zqev0*zqevt/(zqevt+zqevti) |
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| 214 | zqevi=zqev0*zqevti/(zqevt+zqevti) |
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| 215 | ELSE |
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| 216 | zqev=zqevt |
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| 217 | zqevi=zqevti |
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| 218 | ENDIF |
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| 219 | |
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| 220 | !--Diagnostics |
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| 221 | dqreva(i) = - zqev / dtime |
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| 222 | dqssub(i) = - zqevti / dtime |
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| 223 | |
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| 224 | ! New solid and liquid precipitation fluxes after evap and sublimation |
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| 225 | zrfln(i) = Max(0.,zrfl(i) - zqev*(paprsdn(i)-paprsup(i))/RG/dtime) |
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| 226 | zifln(i) = Max(0.,zifl(i) - zqevi*(paprsdn(i)-paprsup(i))/RG/dtime) |
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| 227 | |
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| 228 | |
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| 229 | ! vapor, temperature, precip fluxes update |
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| 230 | ! vapor is updated after evaporation/sublimation (it is increased) |
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| 231 | zq(i) = zq(i) - (zrfln(i)+zifln(i)-zrfl(i)-zifl(i)) & |
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| 232 | * (RG/(paprsdn(i)-paprsup(i)))*dtime |
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| 233 | ! zmqc is the total condensed water in the precip flux (it is decreased) |
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| 234 | zmqc(i) = zmqc(i) + (zrfln(i)+zifln(i)-zrfl(i)-zifl(i)) & |
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| 235 | * (RG/(paprsdn(i)-paprsup(i)))*dtime |
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| 236 | ! air and precip temperature (i.e., gridbox temperature) |
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| 237 | ! is updated due to latent heat cooling |
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| 238 | zt(i) = zt(i) + (zrfln(i)-zrfl(i)) & |
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| 239 | * (RG/(paprsdn(i)-paprsup(i)))*dtime & |
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| 240 | * RLVTT/RCPD/(1.0+RVTMP2*(zq(i)+zmqc(i))) & |
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| 241 | + (zifln(i)-zifl(i)) & |
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| 242 | * (RG/(paprsdn(i)-paprsup(i)))*dtime & |
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| 243 | * RLSTT/RCPD/(1.0+RVTMP2*(zq(i)+zmqc(i))) |
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| 244 | |
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| 245 | ! New values of liquid and solid precipitation |
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| 246 | zrfl(i) = zrfln(i) |
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| 247 | zifl(i) = zifln(i) |
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| 248 | |
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| 249 | ! c_iso here call_reevap that updates isotopic zrfl, zifl (in inout) |
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| 250 | ! due to evap + sublim |
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| 251 | |
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| 252 | |
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| 253 | IF (iflag_evap_prec.GE.4) THEN |
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| 254 | zrflclr(i) = zrfl(i) |
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| 255 | ziflclr(i) = zifl(i) |
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| 256 | IF(zrflclr(i) + ziflclr(i).LE.0) THEN |
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| 257 | znebprecipclr(i) = 0.0 |
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| 258 | ENDIF |
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| 259 | zrfl(i) = zrflclr(i) + zrflcld(i) |
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| 260 | zifl(i) = ziflclr(i) + ziflcld(i) |
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| 261 | ENDIF |
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| 262 | |
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| 263 | ! c_iso duplicate for isotopes or loop on isotopes |
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| 264 | |
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| 265 | ! Melting: |
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| 266 | zmelt = ((zt(i)-RTT)/(ztfondue-RTT)) ! JYG |
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| 267 | ! precip fraction that is melted |
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| 268 | zmelt = MIN(MAX(zmelt,0.),1.) |
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| 269 | |
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| 270 | ! update of rainfall and snowfall due to melting |
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| 271 | IF (iflag_evap_prec.GE.4) THEN |
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| 272 | zrflclr(i)=zrflclr(i)+zmelt*ziflclr(i) |
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| 273 | zrflcld(i)=zrflcld(i)+zmelt*ziflcld(i) |
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| 274 | zrfl(i)=zrflclr(i)+zrflcld(i) |
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| 275 | ELSE |
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| 276 | zrfl(i)=zrfl(i)+zmelt*zifl(i) |
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| 277 | ENDIF |
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| 278 | |
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| 279 | |
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| 280 | ! c_iso: melting of isotopic precipi with zmelt (no fractionation) |
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| 281 | |
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| 282 | ! Latent heat of melting because of precipitation melting |
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| 283 | ! NB: the air + precip temperature is simultaneously updated |
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| 284 | zt(i)=zt(i)-zifl(i)*zmelt*(RG*dtime)/(paprsdn(i)-paprsup(i)) & |
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| 285 | *RLMLT/RCPD/(1.0+RVTMP2*(zq(i)+zmqc(i))) |
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| 286 | |
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| 287 | IF (iflag_evap_prec.GE.4) THEN |
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| 288 | ziflclr(i)=ziflclr(i)*(1.-zmelt) |
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| 289 | ziflcld(i)=ziflcld(i)*(1.-zmelt) |
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| 290 | zifl(i)=ziflclr(i)+ziflcld(i) |
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| 291 | ELSE |
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| 292 | zifl(i)=zifl(i)*(1.-zmelt) |
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| 293 | ENDIF |
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| 294 | |
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| 295 | ELSE |
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| 296 | ! if no precip, we reinitialize the cloud fraction used for the precip to 0 |
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| 297 | znebprecip(i)=0. |
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| 298 | |
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| 299 | ENDIF ! (zrfl(i)+zifl(i).GT.0.) |
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| 300 | |
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| 301 | ENDDO ! loop on klon |
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| 302 | |
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| 303 | ENDIF ! (iflag_evap_prec>=1) |
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| 304 | |
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| 305 | END SUBROUTINE histprecip_precld |
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| 306 | |
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| 307 | |
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[5413] | 308 | SUBROUTINE histprecip_postcld( & |
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| 309 | klon, dtime, iftop, paprsdn, paprsup, pplay, ctot_vol, ptconv, zdqsdT_raw, & |
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| 310 | zt, zq, zoliq, zoliql, zoliqi, zcond, zfice, zmqc, & |
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| 311 | rneb, znebprecipclr, znebprecipcld, zneb, tot_zneb, zrho_up, zvelo_up, & |
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| 312 | zrfl, zrflclr, zrflcld, zifl, ziflclr, ziflcld, & |
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| 313 | zradocond, zradoice, dqrauto, dqsauto & |
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| 314 | ) |
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| 315 | |
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| 316 | USE lmdz_lscp_ini, ONLY : RD, RG, RCPD, RVTMP2, RLSTT, RLMLT, RTT |
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| 317 | USE lmdz_lscp_ini, ONLY : cld_lc_con, cld_tau_con, cld_expo_con, ffallv_con, & |
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| 318 | cld_lc_lsc, cld_tau_lsc, cld_expo_lsc, ffallv_lsc, & |
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| 319 | seuil_neb, rain_int_min, cice_velo, dice_velo |
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| 320 | USE lmdz_lscp_ini, ONLY : iflag_evap_prec, iflag_cloudth_vert, iflag_rain_incloud_vol, & |
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| 321 | iflag_autoconversion, ok_radocond_snow, ok_bug_phase_lscp, & |
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| 322 | niter_lscp |
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| 323 | USE lmdz_lscp_tools, ONLY : fallice_velocity |
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| 324 | |
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| 325 | IMPLICIT NONE |
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| 326 | |
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| 327 | |
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| 328 | INTEGER, INTENT(IN) :: klon !--number of horizontal grid points [-] |
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| 329 | REAL, INTENT(IN) :: dtime !--time step [s] |
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| 330 | LOGICAL, INTENT(IN) :: iftop !--if top of the column |
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| 331 | |
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| 332 | REAL, INTENT(IN), DIMENSION(klon) :: paprsdn !--pressure at the bottom interface of the layer [Pa] |
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| 333 | REAL, INTENT(IN), DIMENSION(klon) :: paprsup !--pressure at the top interface of the layer [Pa] |
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| 334 | REAL, INTENT(IN), DIMENSION(klon) :: pplay !--pressure in the middle of the layer [Pa] |
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| 335 | REAL, INTENT(IN), DIMENSION(klon) :: ctot_vol !--volumic cloud fraction [-] |
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| 336 | LOGICAL, INTENT(IN), DIMENSION(klon) :: ptconv !--true if we are in a convective point |
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| 337 | REAL, INTENT(IN), DIMENSION(klon) :: zdqsdT_raw !--derivative of qsat w.r.t. temperature times L/Cp [SI] |
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| 338 | |
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| 339 | REAL, INTENT(INOUT), DIMENSION(klon) :: zt !--current temperature [K] |
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| 340 | REAL, INTENT(INOUT), DIMENSION(klon) :: zq !--current water vapor specific humidity [kg/kg] |
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| 341 | REAL, INTENT(INOUT), DIMENSION(klon) :: zoliq !--current liquid+ice water specific humidity [kg/kg] |
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| 342 | REAL, INTENT(INOUT), DIMENSION(klon) :: zoliql !--current liquid water specific humidity [kg/kg] |
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| 343 | REAL, INTENT(INOUT), DIMENSION(klon) :: zoliqi !--current ice water specific humidity [kg/kg] |
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| 344 | REAL, INTENT(INOUT), DIMENSION(klon) :: zcond !--liquid+ice water specific humidity AFTER CONDENSATION (no precip process) [kg/kg] |
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| 345 | REAL, INTENT(IN), DIMENSION(klon) :: zfice !--ice fraction AFTER CONDENSATION [-] |
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| 346 | REAL, INTENT(IN), DIMENSION(klon) :: zmqc !--specific humidity in the precipitation falling from the upper layer [kg/kg] |
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| 347 | |
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| 348 | REAL, INTENT(IN), DIMENSION(klon) :: rneb !--cloud fraction [-] |
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| 349 | REAL, INTENT(INOUT), DIMENSION(klon) :: znebprecipclr !--fraction of precipitation in the clear sky IN THE LAYER ABOVE [-] |
---|
| 350 | REAL, INTENT(INOUT), DIMENSION(klon) :: znebprecipcld !--fraction of precipitation in the cloud IN THE LAYER ABOVE [-] |
---|
| 351 | REAL, INTENT(INOUT), DIMENSION(klon) :: zneb !--cloud fraction IN THE LAYER ABOVE [-] |
---|
| 352 | REAL, INTENT(INOUT), DIMENSION(klon) :: tot_zneb !--total cloud cover above the current mesh [-] |
---|
| 353 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrho_up !--air density IN THE LAYER ABOVE [kg/m3] |
---|
| 354 | REAL, INTENT(INOUT), DIMENSION(klon) :: zvelo_up !--ice fallspeed velocity IN THE LAYER ABOVE [m/s] |
---|
| 355 | |
---|
| 356 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrfl !--flux of rain gridbox-mean [kg/s/m2] |
---|
| 357 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrflclr !--flux of rain gridbox-mean in clear sky [kg/s/m2] |
---|
| 358 | REAL, INTENT(INOUT), DIMENSION(klon) :: zrflcld !--flux of rain gridbox-mean in cloudy air [kg/s/m2] |
---|
| 359 | REAL, INTENT(INOUT), DIMENSION(klon) :: zifl !--flux of snow gridbox-mean [kg/s/m2] |
---|
| 360 | REAL, INTENT(INOUT), DIMENSION(klon) :: ziflclr !--flux of snow gridbox-mean in clear sky [kg/s/m2] |
---|
| 361 | REAL, INTENT(INOUT), DIMENSION(klon) :: ziflcld !--flux of snow gridbox-mean in cloudy air [kg/s/m2] |
---|
| 362 | |
---|
| 363 | REAL, INTENT(OUT), DIMENSION(klon) :: zradocond !--condensed water used in the radiation scheme [kg/kg] |
---|
| 364 | REAL, INTENT(OUT), DIMENSION(klon) :: zradoice !--condensed ice water used in the radiation scheme [kg/kg] |
---|
| 365 | REAL, INTENT(OUT), DIMENSION(klon) :: dqrauto !--rain tendency due to autoconversion of cloud liquid [kg/kg/s] |
---|
| 366 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsauto !--snow tendency due to autoconversion of cloud ice [kg/kg/s] |
---|
| 367 | |
---|
| 368 | |
---|
| 369 | ! Local variables for precip fraction update |
---|
| 370 | REAL :: smallestreal |
---|
| 371 | REAL, DIMENSION(klon) :: tot_znebn, d_tot_zneb |
---|
| 372 | REAL, DIMENSION(klon) :: d_znebprecip_cld_clr, d_znebprecip_clr_cld |
---|
| 373 | REAL, DIMENSION(klon) :: d_zrfl_cld_clr, d_zifl_cld_clr |
---|
| 374 | REAL, DIMENSION(klon) :: d_zrfl_clr_cld, d_zifl_clr_cld |
---|
| 375 | |
---|
| 376 | ! Local variables for autoconversion |
---|
| 377 | REAL :: zct, zcl, zexpo, ffallv |
---|
| 378 | REAL :: zchau, zfroi |
---|
| 379 | REAL :: zrain, zsnow, zprecip |
---|
| 380 | REAL :: effective_zneb |
---|
| 381 | REAL, DIMENSION(klon) :: zrho, zvelo |
---|
| 382 | REAL, DIMENSION(klon) :: zdz, iwc |
---|
| 383 | |
---|
| 384 | ! Local variables for Bergeron process |
---|
| 385 | REAL :: zcp, coef1, DeltaT, Deltaq, Deltaqprecl |
---|
| 386 | REAL, DIMENSION(klon) :: zqpreci, zqprecl |
---|
| 387 | |
---|
| 388 | ! Local variables for calculation of quantity of condensates seen by the radiative scheme |
---|
| 389 | REAL, DIMENSION(klon) :: zradoliq |
---|
| 390 | REAL, DIMENSION(klon) :: ziflprev |
---|
| 391 | |
---|
| 392 | ! Misc |
---|
| 393 | INTEGER :: i, n |
---|
| 394 | |
---|
| 395 | ! Initialisation |
---|
| 396 | smallestreal=1.e-9 |
---|
| 397 | zqprecl(:) = 0. |
---|
| 398 | zqpreci(:) = 0. |
---|
| 399 | ziflprev(:) = 0. |
---|
| 400 | |
---|
| 401 | |
---|
| 402 | IF (iflag_evap_prec .GE. 4) THEN |
---|
| 403 | |
---|
| 404 | !Partitionning between precipitation coming from clouds and that coming from CS |
---|
| 405 | |
---|
| 406 | !0) Calculate tot_zneb, total cloud fraction above the cloud |
---|
| 407 | !assuming a maximum-random overlap (voir Jakob and Klein, 2000) |
---|
| 408 | |
---|
| 409 | DO i=1, klon |
---|
| 410 | tot_znebn(i) = 1. - (1.-tot_zneb(i))*(1 - max(rneb(i),zneb(i))) & |
---|
| 411 | /(1.-min(zneb(i),1.-smallestreal)) |
---|
| 412 | d_tot_zneb(i) = tot_znebn(i) - tot_zneb(i) |
---|
| 413 | tot_zneb(i) = tot_znebn(i) |
---|
| 414 | |
---|
| 415 | |
---|
| 416 | !1) Cloudy to clear air |
---|
| 417 | d_znebprecip_cld_clr(i) = znebprecipcld(i) - min(rneb(i),znebprecipcld(i)) |
---|
| 418 | IF (znebprecipcld(i) .GT. 0.) THEN |
---|
| 419 | d_zrfl_cld_clr(i) = d_znebprecip_cld_clr(i)/znebprecipcld(i)*zrflcld(i) |
---|
| 420 | d_zifl_cld_clr(i) = d_znebprecip_cld_clr(i)/znebprecipcld(i)*ziflcld(i) |
---|
| 421 | ELSE |
---|
| 422 | d_zrfl_cld_clr(i) = 0. |
---|
| 423 | d_zifl_cld_clr(i) = 0. |
---|
| 424 | ENDIF |
---|
| 425 | |
---|
| 426 | !2) Clear to cloudy air |
---|
| 427 | d_znebprecip_clr_cld(i) = max(0., min(znebprecipclr(i), rneb(i) - d_tot_zneb(i) - zneb(i))) |
---|
| 428 | IF (znebprecipclr(i) .GT. 0) THEN |
---|
| 429 | d_zrfl_clr_cld(i) = d_znebprecip_clr_cld(i)/znebprecipclr(i)*zrflclr(i) |
---|
| 430 | d_zifl_clr_cld(i) = d_znebprecip_clr_cld(i)/znebprecipclr(i)*ziflclr(i) |
---|
| 431 | ELSE |
---|
| 432 | d_zrfl_clr_cld(i) = 0. |
---|
| 433 | d_zifl_clr_cld(i) = 0. |
---|
| 434 | ENDIF |
---|
| 435 | |
---|
| 436 | !Update variables |
---|
| 437 | znebprecipcld(i) = znebprecipcld(i) + d_znebprecip_clr_cld(i) - d_znebprecip_cld_clr(i) |
---|
| 438 | znebprecipclr(i) = znebprecipclr(i) + d_znebprecip_cld_clr(i) - d_znebprecip_clr_cld(i) |
---|
| 439 | zrflcld(i) = zrflcld(i) + d_zrfl_clr_cld(i) - d_zrfl_cld_clr(i) |
---|
| 440 | ziflcld(i) = ziflcld(i) + d_zifl_clr_cld(i) - d_zifl_cld_clr(i) |
---|
| 441 | zrflclr(i) = zrflclr(i) + d_zrfl_cld_clr(i) - d_zrfl_clr_cld(i) |
---|
| 442 | ziflclr(i) = ziflclr(i) + d_zifl_cld_clr(i) - d_zifl_clr_cld(i) |
---|
| 443 | |
---|
| 444 | ! c_iso do the same thing for isotopes precip |
---|
| 445 | ENDDO |
---|
| 446 | ENDIF |
---|
| 447 | |
---|
| 448 | |
---|
| 449 | ! Autoconversion |
---|
| 450 | ! ------------------------------------------------------------------------------- |
---|
| 451 | |
---|
| 452 | ! Initialisation |
---|
| 453 | DO i = 1, klon |
---|
| 454 | zrho(i) = pplay(i) / zt(i) / RD |
---|
| 455 | zdz(i) = (paprsdn(i)-paprsup(i)) / (zrho(i)*RG) |
---|
| 456 | iwc(i) = 0. |
---|
| 457 | zneb(i) = MAX(rneb(i),seuil_neb) |
---|
| 458 | |
---|
| 459 | ! variables for calculation of quantity of condensates seen by the radiative scheme |
---|
| 460 | ! NB. only zradocond and zradoice are outputed, but zradoliq is used if ok_radocond_snow |
---|
| 461 | ! is TRUE |
---|
| 462 | zradocond(i) = zoliq(i)/REAL(niter_lscp+1) |
---|
| 463 | zradoliq(i) = zoliq(i)*(1.-zfice(i))/REAL(niter_lscp+1) |
---|
| 464 | zradoice(i) = zoliq(i)*zfice(i)/REAL(niter_lscp+1) |
---|
| 465 | ENDDO |
---|
| 466 | |
---|
| 467 | |
---|
| 468 | DO n = 1, niter_lscp |
---|
| 469 | |
---|
| 470 | DO i=1,klon |
---|
| 471 | IF (rneb(i).GT.0.0) THEN |
---|
| 472 | iwc(i) = zrho(i) * zoliqi(i) / zneb(i) ! in-cloud ice condensate content |
---|
| 473 | ENDIF |
---|
| 474 | ENDDO |
---|
| 475 | |
---|
| 476 | CALL fallice_velocity(klon, iwc, zt, zrho, pplay, ptconv, zvelo) |
---|
| 477 | |
---|
| 478 | DO i = 1, klon |
---|
| 479 | |
---|
| 480 | IF (rneb(i).GT.0.0) THEN |
---|
| 481 | |
---|
| 482 | ! Initialization of zrain, zsnow and zprecip: |
---|
| 483 | zrain=0. |
---|
| 484 | zsnow=0. |
---|
| 485 | zprecip=0. |
---|
| 486 | ! c_iso same init for isotopes. Externalisation? |
---|
| 487 | |
---|
| 488 | IF (zneb(i).EQ.seuil_neb) THEN |
---|
| 489 | zprecip = 0.0 |
---|
| 490 | zsnow = 0.0 |
---|
| 491 | zrain= 0.0 |
---|
| 492 | ELSE |
---|
| 493 | |
---|
| 494 | IF (ptconv(i)) THEN ! if convective point |
---|
| 495 | zcl=cld_lc_con |
---|
| 496 | zct=1./cld_tau_con |
---|
| 497 | zexpo=cld_expo_con |
---|
| 498 | ffallv=ffallv_con |
---|
| 499 | ELSE |
---|
| 500 | zcl=cld_lc_lsc |
---|
| 501 | zct=1./cld_tau_lsc |
---|
| 502 | zexpo=cld_expo_lsc |
---|
| 503 | ffallv=ffallv_lsc |
---|
| 504 | ENDIF |
---|
| 505 | |
---|
| 506 | |
---|
| 507 | ! if vertical heterogeneity is taken into account, we use |
---|
| 508 | ! the "true" volume fraction instead of a modified |
---|
| 509 | ! surface fraction (which is larger and artificially |
---|
| 510 | ! reduces the in-cloud water). |
---|
| 511 | IF ((iflag_cloudth_vert.GE.3).AND.(iflag_rain_incloud_vol.EQ.1)) THEN |
---|
| 512 | effective_zneb=ctot_vol(i) |
---|
| 513 | ELSE |
---|
| 514 | effective_zneb=zneb(i) |
---|
| 515 | ENDIF |
---|
| 516 | |
---|
| 517 | |
---|
| 518 | ! Liquid water quantity to remove: zchau (Sundqvist, 1978) |
---|
| 519 | ! dqliq/dt=-qliq/tau*(1-exp(-qcin/clw)**2) |
---|
| 520 | !......................................................... |
---|
| 521 | IF (iflag_autoconversion .EQ. 2) THEN |
---|
| 522 | ! two-steps resolution with niter_lscp=1 sufficient |
---|
| 523 | ! we first treat the second term (with exponential) in an explicit way |
---|
| 524 | ! and then treat the first term (-q/tau) in an exact way |
---|
| 525 | zchau=zoliql(i)*(1.-exp(-dtime/REAL(niter_lscp)*zct & |
---|
| 526 | *(1.-exp(-(zoliql(i)/effective_zneb/zcl)**zexpo)))) |
---|
| 527 | ELSE |
---|
| 528 | ! old explicit resolution with subtimesteps |
---|
| 529 | zchau = zct*dtime/REAL(niter_lscp)*zoliql(i) & |
---|
| 530 | *(1.0-EXP(-(zoliql(i)/effective_zneb/zcl)**zexpo)) |
---|
| 531 | ENDIF |
---|
| 532 | |
---|
| 533 | |
---|
| 534 | ! Ice water quantity to remove (Zender & Kiehl, 1997) |
---|
| 535 | ! dqice/dt=1/rho*d(rho*wice*qice)/dz |
---|
| 536 | !.................................... |
---|
| 537 | IF (iflag_autoconversion .EQ. 2) THEN |
---|
| 538 | ! exact resolution, niter_lscp=1 is sufficient but works only |
---|
| 539 | ! with iflag_vice=0 |
---|
| 540 | IF (zoliqi(i) .GT. 0.) THEN |
---|
| 541 | zfroi=(zoliqi(i)-((zoliqi(i)**(-dice_velo)) & |
---|
| 542 | +dice_velo*dtime/REAL(niter_lscp)*cice_velo/zdz(i)*ffallv)**(-1./dice_velo)) |
---|
| 543 | ELSE |
---|
| 544 | zfroi=0. |
---|
| 545 | ENDIF |
---|
| 546 | ELSE |
---|
| 547 | ! old explicit resolution with subtimesteps |
---|
| 548 | zfroi = dtime/REAL(niter_lscp)/zdz(i)*zoliqi(i)*zvelo(i) |
---|
| 549 | ENDIF |
---|
| 550 | |
---|
| 551 | zrain = MIN(MAX(zchau,0.0),zoliql(i)) |
---|
| 552 | zsnow = MIN(MAX(zfroi,0.0),zoliqi(i)) |
---|
| 553 | zprecip = MAX(zrain + zsnow,0.0) |
---|
| 554 | |
---|
| 555 | ENDIF |
---|
| 556 | |
---|
| 557 | |
---|
| 558 | IF (iflag_autoconversion .GE. 1) THEN |
---|
| 559 | ! debugged version with phase conservation through the autoconversion process |
---|
| 560 | zoliql(i) = MAX(zoliql(i)-1.*zrain , 0.0) |
---|
| 561 | zoliqi(i) = MAX(zoliqi(i)-1.*zsnow , 0.0) |
---|
| 562 | zoliq(i) = MAX(zoliq(i)-zprecip , 0.0) |
---|
| 563 | ELSE |
---|
| 564 | ! bugged version with phase resetting |
---|
| 565 | zoliql(i) = MAX(zoliq(i)*(1.-zfice(i))-1.*zrain , 0.0) |
---|
| 566 | zoliqi(i) = MAX(zoliq(i)*zfice(i)-1.*zsnow , 0.0) |
---|
| 567 | zoliq(i) = MAX(zoliq(i)-zprecip , 0.0) |
---|
| 568 | ENDIF |
---|
| 569 | |
---|
| 570 | ! c_iso: call isotope_conversion (for readibility) or duplicate |
---|
| 571 | |
---|
| 572 | ! variables for calculation of quantity of condensates seen by the radiative scheme |
---|
| 573 | zradocond(i) = zradocond(i) + zoliq(i)/REAL(niter_lscp+1) |
---|
| 574 | zradoliq(i) = zradoliq(i) + zoliql(i)/REAL(niter_lscp+1) |
---|
| 575 | zradoice(i) = zradoice(i) + zoliqi(i)/REAL(niter_lscp+1) |
---|
| 576 | |
---|
| 577 | !--Diagnostics |
---|
| 578 | dqrauto(i) = dqrauto(i) + zrain / dtime |
---|
| 579 | dqsauto(i) = dqsauto(i) + zsnow / dtime |
---|
| 580 | |
---|
| 581 | ENDIF ! rneb >0 |
---|
| 582 | |
---|
| 583 | ENDDO ! i = 1,klon |
---|
| 584 | |
---|
| 585 | ENDDO ! n = 1,niter |
---|
| 586 | |
---|
| 587 | ! Precipitation flux calculation |
---|
| 588 | |
---|
| 589 | DO i = 1, klon |
---|
| 590 | |
---|
| 591 | IF (iflag_evap_prec.GE.4) THEN |
---|
| 592 | ziflprev(i)=ziflcld(i) |
---|
| 593 | ELSE |
---|
| 594 | ziflprev(i)=zifl(i)*zneb(i) |
---|
| 595 | ENDIF |
---|
| 596 | |
---|
| 597 | IF (rneb(i) .GT. 0.0) THEN |
---|
| 598 | |
---|
| 599 | ! CR&JYG: We account for the Wegener-Findeisen-Bergeron process in the precipitation flux: |
---|
| 600 | ! If T<0C, liquid precip are converted into ice, which leads to an increase in |
---|
| 601 | ! temperature DeltaT. The effect of DeltaT on condensates and precipitation is roughly |
---|
| 602 | ! taken into account through a linearization of the equations and by approximating |
---|
| 603 | ! the liquid precipitation process with a "threshold" process. We assume that |
---|
| 604 | ! condensates are not modified during this operation. Liquid precipitation is |
---|
| 605 | ! removed (in the limit DeltaT<273.15-T). Solid precipitation increases. |
---|
| 606 | ! Water vapor increases as well |
---|
| 607 | ! Note that compared to fisrtilp, we always assume iflag_bergeron=2 |
---|
| 608 | |
---|
| 609 | IF (ok_bug_phase_lscp) THEN |
---|
| 610 | zqpreci(i)=(zcond(i)-zoliq(i))*zfice(i) |
---|
| 611 | zqprecl(i)=(zcond(i)-zoliq(i))*(1.-zfice(i)) |
---|
| 612 | ELSE |
---|
| 613 | zqpreci(i)=zcond(i)*zfice(i)-zoliqi(i) |
---|
| 614 | zqprecl(i)=zcond(i)*(1.-zfice(i))-zoliql(i) |
---|
| 615 | ENDIF |
---|
| 616 | zcp=RCPD*(1.0+RVTMP2*(zq(i)+zmqc(i)+zcond(i))) |
---|
| 617 | coef1 = rneb(i)*RLSTT/zcp*zdqsdT_raw(i) |
---|
| 618 | ! Computation of DT if all the liquid precip freezes |
---|
| 619 | DeltaT = RLMLT*zqprecl(i) / (zcp*(1.+coef1)) |
---|
| 620 | ! T should not exceed the freezing point |
---|
| 621 | ! that is Delta > RTT-zt(i) |
---|
| 622 | DeltaT = max( min( RTT-zt(i), DeltaT) , 0. ) |
---|
| 623 | zt(i) = zt(i) + DeltaT |
---|
| 624 | ! water vaporization due to temp. increase |
---|
| 625 | Deltaq = rneb(i)*zdqsdT_raw(i)*DeltaT |
---|
| 626 | ! we add this vaporized water to the total vapor and we remove it from the precip |
---|
| 627 | zq(i) = zq(i) + Deltaq |
---|
| 628 | ! The three "max" lines herebelow protect from rounding errors |
---|
| 629 | zcond(i) = max( zcond(i)- Deltaq, 0. ) |
---|
| 630 | ! liquid precipitation converted to ice precip |
---|
| 631 | Deltaqprecl = -zcp/RLMLT*(1.+coef1)*DeltaT |
---|
| 632 | zqprecl(i) = max( zqprecl(i) + Deltaqprecl, 0. ) |
---|
| 633 | ! iced water budget |
---|
| 634 | zqpreci(i) = max (zqpreci(i) - Deltaqprecl - Deltaq, 0.) |
---|
| 635 | |
---|
| 636 | ! c_iso : mv here condensation of isotopes + redispatchage en precip |
---|
| 637 | |
---|
| 638 | IF (iflag_evap_prec.GE.4) THEN |
---|
| 639 | zrflcld(i) = zrflcld(i)+zqprecl(i) & |
---|
| 640 | *(paprsdn(i)-paprsup(i))/(RG*dtime) |
---|
| 641 | ziflcld(i) = ziflcld(i)+ zqpreci(i) & |
---|
| 642 | *(paprsdn(i)-paprsup(i))/(RG*dtime) |
---|
| 643 | znebprecipcld(i) = rneb(i) |
---|
| 644 | zrfl(i) = zrflcld(i) + zrflclr(i) |
---|
| 645 | zifl(i) = ziflcld(i) + ziflclr(i) |
---|
| 646 | ELSE |
---|
| 647 | zrfl(i) = zrfl(i)+ zqprecl(i) & |
---|
| 648 | *(paprsdn(i)-paprsup(i))/(RG*dtime) |
---|
| 649 | zifl(i) = zifl(i)+ zqpreci(i) & |
---|
| 650 | *(paprsdn(i)-paprsup(i))/(RG*dtime) |
---|
| 651 | ENDIF |
---|
| 652 | ! c_iso : same for isotopes |
---|
| 653 | |
---|
| 654 | ENDIF ! rneb>0 |
---|
| 655 | |
---|
| 656 | ENDDO |
---|
| 657 | |
---|
| 658 | ! LTP: limit of surface cloud fraction covered by precipitation when the local intensity of the flux is below rain_int_min |
---|
| 659 | ! if iflag_evap_prec>=4 |
---|
| 660 | IF (iflag_evap_prec.GE.4) THEN |
---|
| 661 | |
---|
| 662 | DO i=1,klon |
---|
| 663 | |
---|
| 664 | IF ((zrflclr(i) + ziflclr(i)) .GT. 0. ) THEN |
---|
| 665 | znebprecipclr(i) = min(znebprecipclr(i),max( & |
---|
| 666 | zrflclr(i)/ (MAX(znebprecipclr(i),seuil_neb)*rain_int_min), & |
---|
| 667 | ziflclr(i)/ (MAX(znebprecipclr(i),seuil_neb)*rain_int_min))) |
---|
| 668 | ELSE |
---|
| 669 | znebprecipclr(i)=0.0 |
---|
| 670 | ENDIF |
---|
| 671 | |
---|
| 672 | IF ((zrflcld(i) + ziflcld(i)) .GT. 0.) THEN |
---|
| 673 | znebprecipcld(i) = min(znebprecipcld(i), max( & |
---|
| 674 | zrflcld(i)/ (MAX(znebprecipcld(i),seuil_neb)*rain_int_min), & |
---|
| 675 | ziflcld(i)/ (MAX(znebprecipcld(i),seuil_neb)*rain_int_min))) |
---|
| 676 | ELSE |
---|
| 677 | znebprecipcld(i)=0.0 |
---|
| 678 | ENDIF |
---|
| 679 | ENDDO |
---|
| 680 | |
---|
| 681 | ENDIF |
---|
| 682 | |
---|
| 683 | ! we recalculate zradoice to account for contributions from the precipitation flux |
---|
| 684 | ! if ok_radocond_snow is true |
---|
| 685 | IF ( ok_radocond_snow ) THEN |
---|
| 686 | IF ( .NOT. iftop ) THEN |
---|
| 687 | ! for the solid phase (crystals + snowflakes) |
---|
| 688 | ! we recalculate zradoice by summing |
---|
| 689 | ! the ice content calculated in the mesh |
---|
| 690 | ! + the contribution of the non-evaporated snowfall |
---|
| 691 | ! from the overlying layer |
---|
| 692 | DO i=1,klon |
---|
| 693 | IF (ziflprev(i) .NE. 0.0) THEN |
---|
| 694 | zradoice(i)=zoliqi(i)+zqpreci(i)+ziflprev(i)/zrho_up(i)/zvelo_up(i) |
---|
| 695 | ELSE |
---|
| 696 | zradoice(i)=zoliqi(i)+zqpreci(i) |
---|
| 697 | ENDIF |
---|
| 698 | zradocond(i)=zradoliq(i)+zradoice(i) |
---|
| 699 | ENDDO |
---|
| 700 | ENDIF |
---|
| 701 | ! keep in memory air density and ice fallspeed velocity |
---|
| 702 | zrho_up(:) = zrho(:) |
---|
| 703 | zvelo_up(:) = zvelo(:) |
---|
| 704 | ENDIF |
---|
| 705 | |
---|
| 706 | END SUBROUTINE histprecip_postcld |
---|
| 707 | |
---|
| 708 | |
---|
[5408] | 709 | !---------------------------------------------------------------- |
---|
| 710 | ! Computes the processes-oriented precipitation formulations for |
---|
| 711 | ! evaporation and sublimation |
---|
| 712 | ! |
---|
| 713 | SUBROUTINE poprecip_precld( & |
---|
| 714 | klon, dtime, iftop, paprsdn, paprsup, pplay, temp, tempupnew, qvap, & |
---|
| 715 | qprecip, precipfracclr, precipfraccld, qvapclrup, qtotupnew, & |
---|
[5431] | 716 | cldfra, rvc_seri, qliq, qice, & |
---|
[5408] | 717 | rain, rainclr, raincld, snow, snowclr, snowcld, dqreva, dqssub & |
---|
| 718 | ) |
---|
| 719 | |
---|
| 720 | USE lmdz_lscp_ini, ONLY : prt_level, lunout |
---|
| 721 | USE lmdz_lscp_ini, ONLY : coef_eva, coef_sub, expo_eva, expo_sub, thresh_precip_frac |
---|
| 722 | USE lmdz_lscp_ini, ONLY : RCPD, RLSTT, RLVTT, RLMLT, RVTMP2, RTT, RD, RG |
---|
[5431] | 723 | USE lmdz_lscp_ini, ONLY : ok_corr_vap_evasub, ok_ice_supersat, ok_unadjusted_clouds |
---|
| 724 | USE lmdz_lscp_ini, ONLY : eps, temp_nowater |
---|
[5408] | 725 | USE lmdz_lscp_tools, ONLY : calc_qsat_ecmwf |
---|
| 726 | |
---|
| 727 | IMPLICIT NONE |
---|
| 728 | |
---|
| 729 | |
---|
| 730 | INTEGER, INTENT(IN) :: klon !--number of horizontal grid points [-] |
---|
| 731 | REAL, INTENT(IN) :: dtime !--time step [s] |
---|
| 732 | LOGICAL, INTENT(IN) :: iftop !--if top of the column |
---|
| 733 | |
---|
| 734 | |
---|
| 735 | REAL, INTENT(IN), DIMENSION(klon) :: paprsdn !--pressure at the bottom interface of the layer [Pa] |
---|
| 736 | REAL, INTENT(IN), DIMENSION(klon) :: paprsup !--pressure at the top interface of the layer [Pa] |
---|
| 737 | REAL, INTENT(IN), DIMENSION(klon) :: pplay !--pressure in the middle of the layer [Pa] |
---|
| 738 | |
---|
| 739 | REAL, INTENT(INOUT), DIMENSION(klon) :: temp !--current temperature [K] |
---|
| 740 | REAL, INTENT(IN), DIMENSION(klon) :: tempupnew !--updated temperature of the overlying layer [K] |
---|
| 741 | |
---|
| 742 | REAL, INTENT(INOUT), DIMENSION(klon) :: qvap !--current water vapor specific humidity (includes evaporated qi and ql) [kg/kg] |
---|
| 743 | REAL, INTENT(INOUT), DIMENSION(klon) :: qprecip !--specific humidity in the precipitation falling from the upper layer [kg/kg] |
---|
| 744 | |
---|
| 745 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfracclr !--fraction of precipitation in the clear sky IN THE LAYER ABOVE [-] |
---|
| 746 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfraccld !--fraction of precipitation in the cloudy air IN THE LAYER ABOVE [-] |
---|
| 747 | |
---|
| 748 | REAL, INTENT(IN), DIMENSION(klon) :: qvapclrup !--clear-sky specific humidity IN THE LAYER ABOVE [kg/kg] |
---|
| 749 | REAL, INTENT(IN), DIMENSION(klon) :: qtotupnew !--total specific humidity IN THE LAYER ABOVE [kg/kg] |
---|
| 750 | |
---|
[5431] | 751 | REAL, INTENT(IN), DIMENSION(klon) :: cldfra !--cloud fraction at the beginning of lscp - used only if the cloud properties are advected [-] |
---|
| 752 | REAL, INTENT(IN), DIMENSION(klon) :: rvc_seri !--cloud water vapor at the beginning of lscp (ratio wrt total water) - used only if the cloud properties are advected [kg/kg] |
---|
| 753 | REAL, INTENT(IN), DIMENSION(klon) :: qliq !--liquid water content at the beginning of lscp - used only if the cloud properties are advected [kg/kg] |
---|
| 754 | REAL, INTENT(IN), DIMENSION(klon) :: qice !--ice water content at the beginning of lscp - used only if the cloud properties are advected [kg/kg] |
---|
| 755 | |
---|
| 756 | |
---|
[5408] | 757 | REAL, INTENT(INOUT), DIMENSION(klon) :: rain !--flux of rain gridbox-mean coming from the layer above [kg/s/m2] |
---|
| 758 | REAL, INTENT(INOUT), DIMENSION(klon) :: rainclr !--flux of rain gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
[5431] | 759 | REAL, INTENT(INOUT), DIMENSION(klon) :: raincld !--flux of rain gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
[5408] | 760 | REAL, INTENT(INOUT), DIMENSION(klon) :: snow !--flux of snow gridbox-mean coming from the layer above [kg/s/m2] |
---|
| 761 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowclr !--flux of snow gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
[5431] | 762 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowcld !--flux of snow gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
[5408] | 763 | |
---|
| 764 | REAL, INTENT(OUT), DIMENSION(klon) :: dqreva !--rain tendency due to evaporation [kg/kg/s] |
---|
| 765 | REAL, INTENT(OUT), DIMENSION(klon) :: dqssub !--snow tendency due to sublimation [kg/kg/s] |
---|
| 766 | |
---|
| 767 | |
---|
| 768 | !--Integer for interating over klon |
---|
| 769 | INTEGER :: i |
---|
| 770 | !--dhum_to_dflux: coef to convert a specific quantity variation to a flux variation |
---|
| 771 | REAL, DIMENSION(klon) :: dhum_to_dflux |
---|
[5431] | 772 | !--Air density [kg/m3] and layer thickness [m] |
---|
[5408] | 773 | REAL, DIMENSION(klon) :: rho, dz |
---|
[5431] | 774 | !--Temporary precip fractions and fluxes for the evaporation |
---|
| 775 | REAL, DIMENSION(klon) :: precipfracclr_tmp, precipfraccld_tmp |
---|
| 776 | REAL, DIMENSION(klon) :: rainclr_tmp, raincld_tmp, snowclr_tmp, snowcld_tmp |
---|
[5408] | 777 | |
---|
| 778 | !--Saturation values |
---|
| 779 | REAL, DIMENSION(klon) :: qzero, qsat, dqsat, qsatl, dqsatl, qsati, dqsati |
---|
[5431] | 780 | !--Vapor in the clear sky and cloud |
---|
| 781 | REAL :: qvapclr, qvapcld |
---|
[5408] | 782 | !--Fluxes tendencies because of evaporation and sublimation |
---|
[5431] | 783 | REAL :: dprecip_evasub_max, dprecip_evasub_tot |
---|
| 784 | REAL :: drainclreva, draincldeva, dsnowclrsub, dsnowcldsub |
---|
[5408] | 785 | !--Specific humidity tendencies because of evaporation and sublimation |
---|
| 786 | REAL :: dqrevap, dqssubl |
---|
| 787 | !--Specific heat constant |
---|
| 788 | REAL :: cpair, cpw |
---|
| 789 | |
---|
| 790 | !--Initialisation |
---|
| 791 | qzero(:) = 0. |
---|
| 792 | dqreva(:) = 0. |
---|
| 793 | dqssub(:) = 0. |
---|
| 794 | dqrevap = 0. |
---|
| 795 | dqssubl = 0. |
---|
| 796 | |
---|
| 797 | !-- dhum_to_dflux = rho * dz/dt = 1 / g * dP/dt |
---|
| 798 | dhum_to_dflux(:) = ( paprsdn(:) - paprsup(:) ) / RG / dtime |
---|
| 799 | rho(:) = pplay(:) / temp(:) / RD |
---|
| 800 | dz(:) = ( paprsdn(:) - paprsup(:) ) / RG / rho(:) |
---|
| 801 | |
---|
| 802 | !--Calculation of saturation specific humidity |
---|
| 803 | !--depending on temperature: |
---|
| 804 | CALL calc_qsat_ecmwf(klon,temp(:),qzero(:),pplay(:),RTT,0,.false.,qsat(:),dqsat(:)) |
---|
| 805 | !--wrt liquid water |
---|
| 806 | CALL calc_qsat_ecmwf(klon,temp(:),qzero(:),pplay(:),RTT,1,.false.,qsatl(:),dqsatl(:)) |
---|
| 807 | !--wrt ice |
---|
| 808 | CALL calc_qsat_ecmwf(klon,temp(:),qzero(:),pplay(:),RTT,2,.false.,qsati(:),dqsati(:)) |
---|
| 809 | |
---|
| 810 | |
---|
| 811 | |
---|
| 812 | !--First step consists in "thermalizing" the layer: |
---|
| 813 | !--as the flux of precip from layer above "advects" some heat (as the precip is at the temperature |
---|
| 814 | !--of the overlying layer) we recalculate a mean temperature that both the air and the precip in the |
---|
| 815 | !--layer have. |
---|
| 816 | |
---|
| 817 | IF (iftop) THEN |
---|
| 818 | |
---|
| 819 | DO i = 1, klon |
---|
| 820 | qprecip(i) = 0. |
---|
| 821 | ENDDO |
---|
| 822 | |
---|
| 823 | ELSE |
---|
| 824 | |
---|
| 825 | DO i = 1, klon |
---|
| 826 | !--No condensed water so cp=cp(vapor+dry air) |
---|
| 827 | !-- RVTMP2=rcpv/rcpd-1 |
---|
| 828 | cpair = RCPD * ( 1. + RVTMP2 * qvap(i) ) |
---|
| 829 | cpw = RCPD * RVTMP2 |
---|
| 830 | !--qprecip has to be thermalized with |
---|
| 831 | !--layer's air so that precipitation at the ground has the |
---|
| 832 | !--same temperature as the lowermost layer |
---|
| 833 | !--we convert the flux into a specific quantity qprecip |
---|
| 834 | qprecip(i) = ( rain(i) + snow(i) ) / dhum_to_dflux(i) |
---|
| 835 | !-- t(i,k+1) + d_t(i,k+1): new temperature of the overlying layer |
---|
| 836 | temp(i) = ( tempupnew(i) * qprecip(i) * cpw + cpair * temp(i) ) & |
---|
| 837 | / ( cpair + qprecip(i) * cpw ) |
---|
| 838 | ENDDO |
---|
| 839 | |
---|
| 840 | ENDIF |
---|
| 841 | |
---|
| 842 | |
---|
[5431] | 843 | !--Initialise the precipitation fractions and fluxes |
---|
| 844 | DO i = 1, klon |
---|
| 845 | precipfracclr_tmp(i) = precipfracclr(i) |
---|
| 846 | precipfraccld_tmp(i) = precipfraccld(i) |
---|
| 847 | rainclr_tmp(i) = rainclr(i) |
---|
| 848 | snowclr_tmp(i) = snowclr(i) |
---|
| 849 | raincld_tmp(i) = raincld(i) |
---|
| 850 | snowcld_tmp(i) = snowcld(i) |
---|
| 851 | ENDDO |
---|
[5408] | 852 | |
---|
[5431] | 853 | !--If we relax the LTP assumption that the cloud is the same than in the |
---|
| 854 | !--gridbox above, we can change the tmp quantities |
---|
| 855 | IF ( ok_ice_supersat ) THEN |
---|
| 856 | !--Update the precipitation fraction using advected cloud fraction |
---|
| 857 | CALL poprecip_fracupdate( & |
---|
| 858 | klon, cldfra, precipfracclr_tmp, precipfraccld_tmp, & |
---|
| 859 | rainclr_tmp, raincld_tmp, snowclr_tmp, snowcld_tmp) |
---|
| 860 | |
---|
| 861 | ! here we could put an ELSE statement and do one iteration of the condensation scheme |
---|
| 862 | ! (but it would only diagnose cloud from lognormal - link with thermals?) |
---|
| 863 | |
---|
| 864 | DO i = 1, klon |
---|
| 865 | !--We cannot have a total fraction greater than the one in the gridbox above |
---|
| 866 | !--because new cloud formation has not yet occured. |
---|
| 867 | !--If this happens, we reduce the precip frac in the cloud, because it can |
---|
| 868 | !--only mean that the cloud fraction at this level is greater than the total |
---|
| 869 | !--precipitation fraction of the level above, and the precip frac in clear sky |
---|
| 870 | !--is zero. |
---|
| 871 | !--NB. this only works because we assume a max-random cloud and precip overlap |
---|
| 872 | precipfraccld_tmp(i) = MIN( precipfraccld_tmp(i), precipfracclr(i) + precipfraccld(i) ) |
---|
| 873 | ENDDO |
---|
| 874 | |
---|
| 875 | ENDIF |
---|
| 876 | !--At this stage, we guarantee that |
---|
| 877 | !-- precipfracclr + precipfraccld = precipfracclr_tmp + precipfraccld_tmp |
---|
| 878 | |
---|
| 879 | |
---|
[5408] | 880 | DO i = 1, klon |
---|
| 881 | |
---|
| 882 | !--If there is precipitation from the layer above |
---|
[5431] | 883 | IF ( ( rain(i) + snow(i) ) .GT. 0. ) THEN |
---|
[5408] | 884 | |
---|
[5431] | 885 | !--Init |
---|
| 886 | drainclreva = 0. |
---|
| 887 | draincldeva = 0. |
---|
| 888 | dsnowclrsub = 0. |
---|
| 889 | dsnowcldsub = 0. |
---|
| 890 | |
---|
| 891 | !--Init the properties of the air where reevaporation occurs |
---|
| 892 | IF ( ok_ice_supersat ) THEN |
---|
| 893 | !--We can diagnose the water vapor in the cloud using the advected |
---|
| 894 | !--water vapor in the cloud and cloud fraction |
---|
| 895 | IF ( ok_unadjusted_clouds .AND. ( cldfra(i) .GT. eps ) ) THEN |
---|
| 896 | qvapcld = rvc_seri(i) * qvap(i) / cldfra(i) |
---|
| 897 | ENDIF |
---|
| 898 | !--We can diagnose completely the water vapor in clear sky, because all |
---|
| 899 | !--the needed variables (ice, liq, vapor in cld, cloud fraction) are |
---|
| 900 | !--advected |
---|
| 901 | !--Note that qvap(i) is the total water in the gridbox |
---|
| 902 | IF ( ( 1. - cldfra(i) ) .GT. eps ) THEN |
---|
| 903 | qvapclr = ( qvap(i) - qice(i) - qliq(i) - rvc_seri(i) * qvap(i) ) / ( 1. - cldfra(i) ) |
---|
| 904 | ENDIF |
---|
| 905 | ELSEIF ( ok_corr_vap_evasub ) THEN |
---|
| 906 | !--Corrected version from Ludo - we use the same water ratio between |
---|
[5408] | 907 | !--the clear and the cloudy sky as in the layer above. This |
---|
| 908 | !--extends the assumption that the cloud fraction is the same |
---|
| 909 | !--as the layer above. This is assumed only for the evap / subl |
---|
| 910 | !--process |
---|
| 911 | !--Note that qvap(i) is the total water in the gridbox, and |
---|
| 912 | !--precipfraccld(i) is the cloud fraction in the layer above |
---|
[5431] | 913 | IF ( ( 1. - precipfraccld(i) ) .GT. eps ) THEN |
---|
| 914 | qvapclr = qvapclrup(i) / qtotupnew(i) * qvap(i) / ( 1. - precipfraccld(i) ) |
---|
| 915 | ENDIF |
---|
[5408] | 916 | ELSE |
---|
| 917 | !--Legacy version from Ludo - we use the total specific humidity |
---|
| 918 | !--for the evap / subl process |
---|
| 919 | qvapclr = qvap(i) |
---|
| 920 | ENDIF |
---|
| 921 | |
---|
[5431] | 922 | !--------------------------- |
---|
| 923 | !-- EVAP / SUBL IN CLEAR SKY |
---|
| 924 | !--------------------------- |
---|
[5408] | 925 | |
---|
[5431] | 926 | IF ( precipfracclr_tmp(i) .GT. eps ) THEN |
---|
[5408] | 927 | |
---|
[5431] | 928 | !--Evaporation of liquid precipitation coming from above |
---|
| 929 | !--in the clear sky only |
---|
| 930 | !--dprecip/dz = -beta*(1-qvap/qsat)*(precip**expo_eva) |
---|
| 931 | !--formula from Sundqvist 1988, Klemp & Wilhemson 1978 |
---|
| 932 | !--Exact explicit formulation (rainclr is resolved exactly, qvap explicitly) |
---|
| 933 | !--which does not need a barrier on rainclr, because included in the formula |
---|
| 934 | drainclreva = precipfracclr_tmp(i) * MAX(0., & |
---|
| 935 | - coef_eva * ( 1. - expo_eva ) * (1. - qvapclr / qsatl(i)) * dz(i) & |
---|
| 936 | + ( rainclr_tmp(i) / precipfracclr_tmp(i) )**( 1. - expo_eva ) & |
---|
| 937 | )**( 1. / ( 1. - expo_eva ) ) - rainclr_tmp(i) |
---|
| 938 | |
---|
| 939 | !--Evaporation is limited by 0 |
---|
| 940 | !--NB. with ok_ice_supersat activated, this barrier should be useless |
---|
| 941 | drainclreva = MIN(0., drainclreva) |
---|
[5408] | 942 | |
---|
| 943 | |
---|
[5431] | 944 | !--Sublimation of the solid precipitation coming from above |
---|
| 945 | !--(same formula as for liquid precip) |
---|
| 946 | !--Exact explicit formulation (snowclr is resolved exactly, qvap explicitly) |
---|
| 947 | !--which does not need a barrier on snowclr, because included in the formula |
---|
| 948 | dsnowclrsub = precipfracclr_tmp(i) * MAX(0., & |
---|
| 949 | - coef_sub * ( 1. - expo_sub ) * (1. - qvapclr / qsati(i)) * dz(i) & |
---|
| 950 | + ( snowclr_tmp(i) / precipfracclr_tmp(i) )**( 1. - expo_sub ) & |
---|
| 951 | )**( 1. / ( 1. - expo_sub ) ) - snowclr_tmp(i) |
---|
[5408] | 952 | |
---|
[5431] | 953 | !--If ice supersaturation is activated, we allow vapor to condense on falling snow |
---|
| 954 | !--i.e., having a positive dsnowclrsub |
---|
| 955 | IF ( .NOT. ok_ice_supersat ) THEN |
---|
| 956 | !--Sublimation is limited by 0 |
---|
| 957 | dsnowclrsub = MIN(0., dsnowclrsub) |
---|
| 958 | ENDIF |
---|
[5408] | 959 | |
---|
| 960 | |
---|
[5431] | 961 | !--Evaporation limit: we ensure that the layer's fraction below |
---|
| 962 | !--the clear sky does not reach saturation. In this case, we |
---|
| 963 | !--redistribute the maximum flux dprecip_evasub_max conserving the ratio liquid/ice |
---|
| 964 | !--Max evaporation is computed not to saturate the clear sky precip fraction |
---|
| 965 | !--(i.e., the fraction where evaporation occurs) |
---|
| 966 | !--It is expressed as a max flux dprecip_evasub_max |
---|
| 967 | |
---|
| 968 | IF ( .NOT. ok_ice_supersat ) THEN |
---|
| 969 | dprecip_evasub_max = MIN(0., ( qvapclr - qsat(i) ) * precipfracclr_tmp(i)) & |
---|
| 970 | * dhum_to_dflux(i) |
---|
| 971 | ELSE |
---|
| 972 | dprecip_evasub_max = ( qvapclr - qsat(i) ) * precipfracclr_tmp(i) & |
---|
| 973 | * dhum_to_dflux(i) |
---|
| 974 | ENDIF |
---|
| 975 | dprecip_evasub_tot = drainclreva + dsnowclrsub |
---|
| 976 | |
---|
| 977 | !--Barriers |
---|
| 978 | !--If activates if the total is LOWER than the max because |
---|
| 979 | !--everything is negative |
---|
| 980 | IF ( (( dprecip_evasub_max .LT. 0. ) .AND. & |
---|
| 981 | ( dprecip_evasub_tot .LT. dprecip_evasub_max )) .OR. & |
---|
| 982 | (( dprecip_evasub_max .GT. 0. ) .AND. & |
---|
| 983 | ( dprecip_evasub_tot .GT. dprecip_evasub_max )) ) THEN |
---|
| 984 | drainclreva = dprecip_evasub_max * drainclreva / dprecip_evasub_tot |
---|
| 985 | dsnowclrsub = dprecip_evasub_max * dsnowclrsub / dprecip_evasub_tot |
---|
| 986 | ENDIF |
---|
| 987 | |
---|
| 988 | ENDIF ! precipfracclr_tmp .GT. eps |
---|
| 989 | |
---|
| 990 | |
---|
| 991 | !--------------------------- |
---|
| 992 | !-- EVAP / SUBL IN THE CLOUD |
---|
| 993 | !--------------------------- |
---|
| 994 | |
---|
| 995 | IF ( ok_unadjusted_clouds .AND. ( temp(i) .LE. temp_nowater ) .AND. ( precipfraccld_tmp(i) .GT. eps ) ) THEN |
---|
| 996 | !--Evaporation of liquid precipitation coming from above |
---|
| 997 | !--in the cloud only |
---|
| 998 | !--dprecip/dz = -beta*(1-qvap/qsat)*(precip**expo_eva) |
---|
| 999 | !--formula from Sundqvist 1988, Klemp & Wilhemson 1978 |
---|
| 1000 | !--Exact explicit formulation (raincld is resolved exactly, qvap explicitly) |
---|
| 1001 | !--which does not need a barrier on raincld, because included in the formula |
---|
| 1002 | !draincldeva = precipfraccld_tmp(i) * MAX(0., & |
---|
| 1003 | ! - coef_eva * ( 1. - expo_eva ) * (1. - qvapcld / qsatl(i)) * dz(i) & |
---|
| 1004 | ! + ( raincld_tmp(i) / precipfraccld_tmp(i) )**( 1. - expo_eva ) & |
---|
| 1005 | ! )**( 1. / ( 1. - expo_eva ) ) - raincld_tmp(i) |
---|
| 1006 | |
---|
| 1007 | !--Evaporation is limited by 0 |
---|
| 1008 | !--NB. with ok_ice_supersat activated, this barrier should be useless |
---|
| 1009 | !draincldeva = MIN(0., draincldeva) |
---|
| 1010 | draincldeva = 0. |
---|
| 1011 | |
---|
| 1012 | |
---|
| 1013 | !--Sublimation of the solid precipitation coming from above |
---|
| 1014 | !--(same formula as for liquid precip) |
---|
| 1015 | !--Exact explicit formulation (snowcld is resolved exactly, qvap explicitly) |
---|
| 1016 | !--which does not need a barrier on snowcld, because included in the formula |
---|
| 1017 | dsnowcldsub = precipfraccld_tmp(i) * MAX(0., & |
---|
| 1018 | - coef_sub * ( 1. - expo_sub ) * (1. - qvapcld / qsati(i)) * dz(i) & |
---|
| 1019 | + ( snowcld_tmp(i) / precipfraccld_tmp(i) )**( 1. - expo_sub ) & |
---|
| 1020 | )**( 1. / ( 1. - expo_sub ) ) - snowcld_tmp(i) |
---|
| 1021 | |
---|
| 1022 | !--There is no barrier because we want deposition to occur if it is possible |
---|
| 1023 | |
---|
| 1024 | |
---|
| 1025 | !--Evaporation limit: we ensure that the layer's fraction below |
---|
| 1026 | !--the clear sky does not reach saturation. In this case, we |
---|
| 1027 | !--redistribute the maximum flux dprecip_evasub_max conserving the ratio liquid/ice |
---|
| 1028 | !--Max evaporation is computed not to saturate the clear sky precip fraction |
---|
| 1029 | !--(i.e., the fraction where evaporation occurs) |
---|
| 1030 | !--It is expressed as a max flux dprecip_evasub_max |
---|
| 1031 | |
---|
| 1032 | dprecip_evasub_max = ( qvapcld - qsat(i) ) * precipfraccld_tmp(i) * dhum_to_dflux(i) |
---|
| 1033 | dprecip_evasub_tot = draincldeva + dsnowcldsub |
---|
| 1034 | |
---|
| 1035 | !--Barriers |
---|
| 1036 | !--If activates if the total is LOWER than the max because |
---|
| 1037 | !--everything is negative |
---|
| 1038 | IF ( (( dprecip_evasub_max .LT. 0. ) .AND. & |
---|
| 1039 | ( dprecip_evasub_tot .LT. dprecip_evasub_max )) .OR. & |
---|
| 1040 | (( dprecip_evasub_max .GT. 0. ) .AND. & |
---|
| 1041 | ( dprecip_evasub_tot .GT. dprecip_evasub_max )) ) THEN |
---|
| 1042 | draincldeva = dprecip_evasub_max * draincldeva / dprecip_evasub_tot |
---|
| 1043 | dsnowcldsub = dprecip_evasub_max * dsnowcldsub / dprecip_evasub_tot |
---|
| 1044 | ENDIF |
---|
| 1045 | |
---|
| 1046 | ENDIF ! ok_unadjusted_clouds |
---|
| 1047 | |
---|
| 1048 | |
---|
[5408] | 1049 | !--New solid and liquid precipitation fluxes after evap and sublimation |
---|
[5431] | 1050 | dqrevap = ( drainclreva + draincldeva ) / dhum_to_dflux(i) |
---|
| 1051 | dqssubl = ( dsnowclrsub + dsnowcldsub ) / dhum_to_dflux(i) |
---|
[5408] | 1052 | |
---|
| 1053 | !--Vapor is updated after evaporation/sublimation (it is increased) |
---|
| 1054 | qvap(i) = qvap(i) - dqrevap - dqssubl |
---|
| 1055 | !--qprecip is the total condensed water in the precip flux (it is decreased) |
---|
| 1056 | qprecip(i) = qprecip(i) + dqrevap + dqssubl |
---|
| 1057 | !--Air and precip temperature (i.e., gridbox temperature) |
---|
| 1058 | !--is updated due to latent heat cooling |
---|
| 1059 | temp(i) = temp(i) & |
---|
| 1060 | + dqrevap * RLVTT / RCPD & |
---|
| 1061 | / ( 1. + RVTMP2 * ( qvap(i) + qprecip(i) ) ) & |
---|
| 1062 | + dqssubl * RLSTT / RCPD & |
---|
| 1063 | / ( 1. + RVTMP2 * ( qvap(i) + qprecip(i) ) ) |
---|
| 1064 | |
---|
| 1065 | !--Add tendencies |
---|
[5431] | 1066 | !--The MAX is needed because in some cases, the flux can be slightly |
---|
| 1067 | !--negative (numerical precision) |
---|
| 1068 | rainclr_tmp(i) = MAX(0., rainclr_tmp(i) + drainclreva) |
---|
| 1069 | snowclr_tmp(i) = MAX(0., snowclr_tmp(i) + dsnowclrsub) |
---|
| 1070 | raincld_tmp(i) = MAX(0., raincld_tmp(i) + draincldeva) |
---|
| 1071 | snowcld_tmp(i) = MAX(0., snowcld_tmp(i) + dsnowcldsub) |
---|
[5408] | 1072 | |
---|
[5431] | 1073 | |
---|
| 1074 | !--We reattribute fluxes according to initial fractions, using proportionnality |
---|
| 1075 | !--Note that trough this process, we conserve total precip fluxes |
---|
| 1076 | !-- rainclr_tmp + raincld_tmp = rainclr + raincld (same for snow) |
---|
| 1077 | !--If the cloud has increased, a part of the precip in clear sky falls in clear sky, |
---|
| 1078 | !--the rest falls in the cloud |
---|
| 1079 | IF ( ( precipfraccld(i) .GT. eps ) .AND. ( precipfraccld_tmp(i) .GT. precipfraccld(i) ) ) THEN |
---|
| 1080 | !--All the precip from cloud falls in the cloud |
---|
| 1081 | raincld(i) = MAX(0., raincld_tmp(i) * precipfraccld(i) / precipfraccld_tmp(i)) |
---|
| 1082 | rainclr(i) = MAX(0., rainclr_tmp(i) + raincld_tmp(i) - raincld(i)) |
---|
| 1083 | snowcld(i) = MAX(0., snowcld_tmp(i) * precipfraccld(i) / precipfraccld_tmp(i)) |
---|
| 1084 | snowclr(i) = MAX(0., snowclr_tmp(i) + snowcld_tmp(i) - snowcld(i)) |
---|
| 1085 | |
---|
| 1086 | !--If the cloud has narrowed, a part of the precip in cloud falls in clear sky, |
---|
| 1087 | !--the rest falls in the cloud |
---|
| 1088 | ELSEIF ( ( precipfracclr(i) .GT. eps ) .AND. ( precipfracclr_tmp(i) .GT. precipfracclr(i) ) ) THEN |
---|
| 1089 | !--All the precip from clear sky falls in clear sky |
---|
| 1090 | rainclr(i) = MAX(0., rainclr_tmp(i) * precipfracclr(i) / precipfracclr_tmp(i)) |
---|
| 1091 | raincld(i) = MAX(0., raincld_tmp(i) + rainclr_tmp(i) - rainclr(i)) |
---|
| 1092 | snowclr(i) = MAX(0., snowclr_tmp(i) * precipfracclr(i) / precipfracclr_tmp(i)) |
---|
| 1093 | snowcld(i) = MAX(0., snowcld_tmp(i) + snowclr_tmp(i) - snowclr(i)) |
---|
| 1094 | |
---|
| 1095 | ELSE |
---|
| 1096 | !--If the cloud stays the same or if there is no cloud above and |
---|
| 1097 | !--in the current layer, there is no reattribution |
---|
| 1098 | rainclr(i) = rainclr_tmp(i) |
---|
| 1099 | raincld(i) = raincld_tmp(i) |
---|
| 1100 | snowclr(i) = snowclr_tmp(i) |
---|
| 1101 | snowcld(i) = snowcld_tmp(i) |
---|
| 1102 | ENDIF |
---|
| 1103 | |
---|
| 1104 | !--If there is no more precip fluxes, the precipitation fraction is set to 0 |
---|
[5408] | 1105 | IF ( ( rainclr(i) + snowclr(i) ) .LE. 0. ) precipfracclr(i) = 0. |
---|
[5431] | 1106 | IF ( ( raincld(i) + snowcld(i) ) .LE. 0. ) precipfraccld(i) = 0. |
---|
[5408] | 1107 | |
---|
| 1108 | !--Calculation of the total fluxes |
---|
| 1109 | rain(i) = rainclr(i) + raincld(i) |
---|
| 1110 | snow(i) = snowclr(i) + snowcld(i) |
---|
| 1111 | |
---|
| 1112 | ELSEIF ( ( rain(i) + snow(i) ) .LE. 0. ) THEN |
---|
| 1113 | !--If no precip, we reinitialize the cloud fraction used for the precip to 0 |
---|
| 1114 | precipfraccld(i) = 0. |
---|
| 1115 | precipfracclr(i) = 0. |
---|
| 1116 | |
---|
| 1117 | ENDIF ! ( ( rain(i) + snow(i) ) .GT. 0. ) |
---|
| 1118 | |
---|
| 1119 | !--Diagnostic tendencies |
---|
| 1120 | dqssub(i) = dqssubl / dtime |
---|
| 1121 | dqreva(i) = dqrevap / dtime |
---|
| 1122 | |
---|
| 1123 | ENDDO ! loop on klon |
---|
| 1124 | |
---|
| 1125 | END SUBROUTINE poprecip_precld |
---|
| 1126 | |
---|
| 1127 | |
---|
| 1128 | !---------------------------------------------------------------- |
---|
[5431] | 1129 | ! Computes the precipitation fraction update |
---|
| 1130 | ! The goal of this routine is to reattribute precipitation fractions |
---|
| 1131 | ! and fluxes to clear or cloudy air, depending on the variation of |
---|
| 1132 | ! the cloud fraction on the vertical dimension. We assume a |
---|
| 1133 | ! maximum-random overlap of the cloud cover (see Jakob and Klein, 2000, |
---|
| 1134 | ! and LTP thesis, 2021) |
---|
| 1135 | ! NB. in fact, we assume a maximum-random overlap of the total precip. frac |
---|
| 1136 | ! |
---|
| 1137 | SUBROUTINE poprecip_fracupdate( & |
---|
| 1138 | klon, cldfra, precipfracclr, precipfraccld, & |
---|
| 1139 | rainclr, raincld, snowclr, snowcld) |
---|
| 1140 | |
---|
| 1141 | USE lmdz_lscp_ini, ONLY : eps |
---|
| 1142 | |
---|
| 1143 | IMPLICIT NONE |
---|
| 1144 | |
---|
| 1145 | INTEGER, INTENT(IN) :: klon !--number of horizontal grid points [-] |
---|
| 1146 | |
---|
| 1147 | REAL, INTENT(IN), DIMENSION(klon) :: cldfra !--cloud fraction [-] |
---|
| 1148 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfracclr !--fraction of precipitation in the clear sky IN THE LAYER ABOVE [-] |
---|
| 1149 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfraccld !--fraction of precipitation in the cloudy air IN THE LAYER ABOVE [-] |
---|
| 1150 | !--NB. at the end of the routine, becomes the fraction of precip |
---|
| 1151 | !--in the current layer |
---|
| 1152 | |
---|
| 1153 | REAL, INTENT(INOUT), DIMENSION(klon) :: rainclr !--flux of rain gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
| 1154 | REAL, INTENT(INOUT), DIMENSION(klon) :: raincld !--flux of rain gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
| 1155 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowclr !--flux of snow gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
| 1156 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowcld !--flux of snow gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
| 1157 | |
---|
| 1158 | !--Local variables |
---|
| 1159 | INTEGER :: i |
---|
| 1160 | REAL :: dcldfra |
---|
| 1161 | REAL :: precipfractot |
---|
| 1162 | REAL :: dprecipfracclr, dprecipfraccld |
---|
| 1163 | REAL :: drainclr, dsnowclr |
---|
| 1164 | REAL :: draincld, dsnowcld |
---|
| 1165 | |
---|
| 1166 | |
---|
| 1167 | DO i = 1, klon |
---|
| 1168 | |
---|
| 1169 | !--Initialisation |
---|
| 1170 | precipfractot = precipfracclr(i) + precipfraccld(i) |
---|
| 1171 | |
---|
| 1172 | !--Instead of using the cloud cover which was use in LTP thesis, we use the |
---|
| 1173 | !--total precip. fraction to compute the maximum-random overlap. This is |
---|
| 1174 | !--because all the information of the cloud cover is embedded into |
---|
| 1175 | !--precipfractot, and this allows for taking into account the potential |
---|
| 1176 | !--reduction of the precipitation fraction because either the flux is too |
---|
| 1177 | !--small (see barrier at the end of poprecip_postcld) or the flux is completely |
---|
| 1178 | !--evaporated (see barrier at the end of poprecip_precld) |
---|
| 1179 | !--NB. precipfraccld(i) is here the cloud fraction of the layer above |
---|
| 1180 | !precipfractot = 1. - ( 1. - precipfractot ) * & |
---|
| 1181 | ! ( 1. - MAX( cldfra(i), precipfraccld(i) ) ) & |
---|
| 1182 | ! / ( 1. - MIN( precipfraccld(i), 1. - eps ) ) |
---|
| 1183 | |
---|
| 1184 | |
---|
| 1185 | IF ( precipfraccld(i) .GT. ( 1. - eps ) ) THEN |
---|
| 1186 | precipfractot = 1. |
---|
| 1187 | ELSE |
---|
| 1188 | precipfractot = 1. - ( 1. - precipfractot ) * & |
---|
| 1189 | ( 1. - MAX( cldfra(i), precipfraccld(i) ) ) & |
---|
| 1190 | / ( 1. - precipfraccld(i) ) |
---|
| 1191 | ENDIF |
---|
| 1192 | |
---|
| 1193 | !--precipfraccld(i) is here the cloud fraction of the layer above |
---|
| 1194 | dcldfra = cldfra(i) - precipfraccld(i) |
---|
| 1195 | !--Tendency of the clear-sky precipitation fraction. We add a MAX on the |
---|
| 1196 | !--calculation of the current CS precip. frac. |
---|
| 1197 | !dprecipfracclr = MAX( 0., ( precipfractot - cldfra(i) ) ) - precipfracclr(i) |
---|
| 1198 | !--We remove it, because precipfractot is guaranteed to be > cldfra (the MAX is activated |
---|
| 1199 | !--if precipfractot < cldfra) |
---|
| 1200 | dprecipfracclr = ( precipfractot - cldfra(i) ) - precipfracclr(i) |
---|
| 1201 | !--Tendency of the cloudy precipitation fraction. We add a MAX on the |
---|
| 1202 | !--calculation of the current CS precip. frac. |
---|
| 1203 | !dprecipfraccld = MAX( dcldfra , - precipfraccld(i) ) |
---|
| 1204 | !--We remove it, because cldfra is guaranteed to be > 0 (the MAX is activated |
---|
| 1205 | !--if cldfra < 0) |
---|
| 1206 | dprecipfraccld = dcldfra |
---|
| 1207 | |
---|
| 1208 | |
---|
| 1209 | !--If the cloud extends |
---|
| 1210 | IF ( dprecipfraccld .GT. 0. ) THEN |
---|
| 1211 | !--If there is no CS precip, nothing happens. |
---|
| 1212 | !--If there is, we reattribute some of the CS precip flux |
---|
| 1213 | !--to the cloud precip flux, proportionnally to the |
---|
| 1214 | !--decrease of the CS precip fraction |
---|
| 1215 | IF ( precipfracclr(i) .LT. eps ) THEN |
---|
| 1216 | drainclr = 0. |
---|
| 1217 | dsnowclr = 0. |
---|
| 1218 | ELSE |
---|
| 1219 | drainclr = dprecipfracclr / precipfracclr(i) * rainclr(i) |
---|
| 1220 | dsnowclr = dprecipfracclr / precipfracclr(i) * snowclr(i) |
---|
| 1221 | ENDIF |
---|
| 1222 | !--If the cloud narrows |
---|
| 1223 | ELSEIF ( dprecipfraccld .LT. 0. ) THEN |
---|
| 1224 | !--We reattribute some of the cloudy precip flux |
---|
| 1225 | !--to the CS precip flux, proportionnally to the |
---|
| 1226 | !--decrease of the cloud precip fraction |
---|
| 1227 | IF ( precipfraccld(i) .LT. eps ) THEN |
---|
| 1228 | draincld = 0. |
---|
| 1229 | dsnowcld = 0. |
---|
| 1230 | ELSE |
---|
| 1231 | draincld = dprecipfraccld / precipfraccld(i) * raincld(i) |
---|
| 1232 | dsnowcld = dprecipfraccld / precipfraccld(i) * snowcld(i) |
---|
| 1233 | ENDIF |
---|
| 1234 | drainclr = - draincld |
---|
| 1235 | dsnowclr = - dsnowcld |
---|
| 1236 | !--If the cloud stays the same or if there is no cloud above and |
---|
| 1237 | !--in the current layer, nothing happens |
---|
| 1238 | ELSE |
---|
| 1239 | drainclr = 0. |
---|
| 1240 | dsnowclr = 0. |
---|
| 1241 | ENDIF |
---|
| 1242 | |
---|
| 1243 | !--We add the tendencies |
---|
| 1244 | !--The MAX is needed because in some cases, the flux can be slightly negative (numerical precision) |
---|
| 1245 | precipfraccld(i) = precipfraccld(i) + dprecipfraccld |
---|
| 1246 | precipfracclr(i) = precipfracclr(i) + dprecipfracclr |
---|
| 1247 | rainclr(i) = MAX(0., rainclr(i) + drainclr) |
---|
| 1248 | snowclr(i) = MAX(0., snowclr(i) + dsnowclr) |
---|
| 1249 | raincld(i) = MAX(0., raincld(i) - drainclr) |
---|
| 1250 | snowcld(i) = MAX(0., snowcld(i) - dsnowclr) |
---|
| 1251 | |
---|
| 1252 | ENDDO |
---|
| 1253 | |
---|
| 1254 | END SUBROUTINE poprecip_fracupdate |
---|
| 1255 | |
---|
| 1256 | |
---|
| 1257 | !---------------------------------------------------------------- |
---|
[5408] | 1258 | ! Computes the processes-oriented precipitation formulations for |
---|
| 1259 | ! - autoconversion (auto) via a deposition process |
---|
| 1260 | ! - aggregation (agg) |
---|
| 1261 | ! - riming (rim) |
---|
| 1262 | ! - collection (col) |
---|
| 1263 | ! - melting (melt) |
---|
| 1264 | ! - freezing (freez) |
---|
| 1265 | ! |
---|
| 1266 | SUBROUTINE poprecip_postcld( & |
---|
| 1267 | klon, dtime, paprsdn, paprsup, pplay, ctot_vol, ptconv, & |
---|
| 1268 | temp, qvap, qliq, qice, icefrac, cldfra, & |
---|
| 1269 | precipfracclr, precipfraccld, & |
---|
| 1270 | rain, rainclr, raincld, snow, snowclr, snowcld, & |
---|
| 1271 | qraindiag, qsnowdiag, dqrauto, dqrcol, dqrmelt, dqrfreez, & |
---|
| 1272 | dqsauto, dqsagg, dqsrim, dqsmelt, dqsfreez) |
---|
| 1273 | |
---|
| 1274 | USE lmdz_lscp_ini, ONLY : prt_level, lunout |
---|
| 1275 | USE lmdz_lscp_ini, ONLY : RCPD, RLSTT, RLVTT, RLMLT, RVTMP2, RTT, RD, RG, RPI |
---|
| 1276 | USE lmdz_lscp_tools, ONLY : calc_qsat_ecmwf |
---|
| 1277 | |
---|
| 1278 | USE lmdz_lscp_ini, ONLY : cld_lc_con, cld_tau_con, cld_expo_con, seuil_neb, & |
---|
| 1279 | cld_lc_lsc, cld_tau_lsc, cld_expo_lsc, rain_int_min, & |
---|
| 1280 | thresh_precip_frac, gamma_col, gamma_agg, gamma_rim, & |
---|
| 1281 | rho_rain, r_rain, r_snow, rho_ice, & |
---|
| 1282 | tau_auto_snow_min, tau_auto_snow_max, & |
---|
| 1283 | thresh_precip_frac, eps, & |
---|
| 1284 | gamma_melt, alpha_freez, beta_freez, temp_nowater, & |
---|
| 1285 | iflag_cloudth_vert, iflag_rain_incloud_vol, & |
---|
| 1286 | cld_lc_lsc_snow, cld_lc_con_snow, gamma_freez, & |
---|
| 1287 | rain_fallspeed_clr, rain_fallspeed_cld, & |
---|
| 1288 | snow_fallspeed_clr, snow_fallspeed_cld |
---|
| 1289 | |
---|
| 1290 | |
---|
| 1291 | IMPLICIT NONE |
---|
| 1292 | |
---|
| 1293 | INTEGER, INTENT(IN) :: klon !--number of horizontal grid points [-] |
---|
| 1294 | REAL, INTENT(IN) :: dtime !--time step [s] |
---|
| 1295 | |
---|
| 1296 | REAL, INTENT(IN), DIMENSION(klon) :: paprsdn !--pressure at the bottom interface of the layer [Pa] |
---|
| 1297 | REAL, INTENT(IN), DIMENSION(klon) :: paprsup !--pressure at the top interface of the layer [Pa] |
---|
| 1298 | REAL, INTENT(IN), DIMENSION(klon) :: pplay !--pressure in the middle of the layer [Pa] |
---|
| 1299 | |
---|
| 1300 | REAL, INTENT(IN), DIMENSION(klon) :: ctot_vol !--volumic cloud fraction [-] |
---|
| 1301 | LOGICAL, INTENT(IN), DIMENSION(klon) :: ptconv !--true if we are in a convective point |
---|
| 1302 | |
---|
| 1303 | REAL, INTENT(INOUT), DIMENSION(klon) :: temp !--current temperature [K] |
---|
| 1304 | REAL, INTENT(INOUT), DIMENSION(klon) :: qvap !--current water vapor specific humidity [kg/kg] |
---|
| 1305 | REAL, INTENT(INOUT), DIMENSION(klon) :: qliq !--current liquid water specific humidity [kg/kg] |
---|
| 1306 | REAL, INTENT(INOUT), DIMENSION(klon) :: qice !--current ice water specific humidity [kg/kg] |
---|
| 1307 | REAL, INTENT(IN), DIMENSION(klon) :: icefrac !--ice fraction [-] |
---|
| 1308 | REAL, INTENT(IN), DIMENSION(klon) :: cldfra !--cloud fraction [-] |
---|
| 1309 | |
---|
| 1310 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfracclr !--fraction of precipitation in the clear sky IN THE LAYER ABOVE [-] |
---|
| 1311 | REAL, INTENT(INOUT), DIMENSION(klon) :: precipfraccld !--fraction of precipitation in the cloudy air IN THE LAYER ABOVE [-] |
---|
| 1312 | !--NB. at the end of the routine, becomes the fraction of precip |
---|
| 1313 | !--in the current layer |
---|
| 1314 | |
---|
| 1315 | REAL, INTENT(INOUT), DIMENSION(klon) :: rain !--flux of rain gridbox-mean coming from the layer above [kg/s/m2] |
---|
| 1316 | REAL, INTENT(INOUT), DIMENSION(klon) :: rainclr !--flux of rain gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
| 1317 | REAL, INTENT(INOUT), DIMENSION(klon) :: raincld !--flux of rain gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
| 1318 | REAL, INTENT(INOUT), DIMENSION(klon) :: snow !--flux of snow gridbox-mean coming from the layer above [kg/s/m2] |
---|
| 1319 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowclr !--flux of snow gridbox-mean in clear sky coming from the layer above [kg/s/m2] |
---|
| 1320 | REAL, INTENT(INOUT), DIMENSION(klon) :: snowcld !--flux of snow gridbox-mean in cloudy air coming from the layer above [kg/s/m2] |
---|
| 1321 | |
---|
| 1322 | REAL, INTENT(OUT), DIMENSION(klon) :: qraindiag !--DIAGNOSTIC specific rain content [kg/kg] |
---|
| 1323 | REAL, INTENT(OUT), DIMENSION(klon) :: qsnowdiag !--DIAGNOSTIC specific snow content [kg/kg] |
---|
| 1324 | REAL, INTENT(OUT), DIMENSION(klon) :: dqrcol !--rain tendendy due to collection by rain of liquid cloud droplets [kg/kg/s] |
---|
| 1325 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsagg !--snow tendency due to collection of lcoud ice by aggregation [kg/kg/s] |
---|
| 1326 | REAL, INTENT(OUT), DIMENSION(klon) :: dqrauto !--rain tendency due to autoconversion of cloud liquid [kg/kg/s] |
---|
| 1327 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsauto !--snow tendency due to autoconversion of cloud ice [kg/kg/s] |
---|
| 1328 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsrim !--snow tendency due to riming [kg/kg/s] |
---|
| 1329 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsmelt !--snow tendency due to melting [kg/kg/s] |
---|
| 1330 | REAL, INTENT(OUT), DIMENSION(klon) :: dqrmelt !--rain tendency due to melting [kg/kg/s] |
---|
| 1331 | REAL, INTENT(OUT), DIMENSION(klon) :: dqsfreez !--snow tendency due to freezing [kg/kg/s] |
---|
| 1332 | REAL, INTENT(OUT), DIMENSION(klon) :: dqrfreez !--rain tendency due to freezing [kg/kg/s] |
---|
| 1333 | |
---|
| 1334 | |
---|
| 1335 | |
---|
| 1336 | !--Local variables |
---|
| 1337 | |
---|
| 1338 | INTEGER :: i |
---|
| 1339 | !--dhum_to_dflux: coef to convert a specific quantity variation to a flux variation |
---|
| 1340 | REAL, DIMENSION(klon) :: dhum_to_dflux |
---|
| 1341 | REAL, DIMENSION(klon) :: qtot !--includes vap, liq, ice and precip |
---|
| 1342 | |
---|
| 1343 | !--Collection, aggregation and riming |
---|
| 1344 | REAL :: eff_cldfra |
---|
| 1345 | REAL :: coef_col, coef_agg, coef_rim, coef_tmp, qrain_tmp |
---|
| 1346 | REAL :: Eff_rain_liq, Eff_snow_ice, Eff_snow_liq |
---|
| 1347 | REAL :: rho_snow |
---|
| 1348 | REAL :: dqlcol !--loss of liquid cloud content due to collection by rain [kg/kg/s] |
---|
| 1349 | REAL :: dqiagg !--loss of ice cloud content due to collection by aggregation [kg/kg/s] |
---|
| 1350 | REAL :: dqlrim !--loss of liquid cloud content due to riming on snow [kg/kg/s] |
---|
| 1351 | |
---|
| 1352 | !--Autoconversion |
---|
| 1353 | REAL :: qthresh_auto_rain, tau_auto_rain, expo_auto_rain |
---|
| 1354 | REAL :: qthresh_auto_snow, tau_auto_snow, expo_auto_snow |
---|
| 1355 | REAL :: dqlauto !--loss of liquid cloud content due to autoconversion to rain [kg/kg/s] |
---|
| 1356 | REAL :: dqiauto !--loss of ice cloud content due to autoconversion to snow [kg/kg/s] |
---|
| 1357 | |
---|
| 1358 | !--Melting |
---|
| 1359 | REAL :: dqsmelt_max, air_thermal_conduct |
---|
| 1360 | REAL :: nb_snowflake_clr, nb_snowflake_cld |
---|
| 1361 | REAL :: capa_snowflake, temp_wetbulb |
---|
| 1362 | REAL :: rho, r_ice |
---|
| 1363 | REAL :: dqsclrmelt, dqscldmelt, dqstotmelt |
---|
| 1364 | REAL, DIMENSION(klon) :: qzero, qsat, dqsat |
---|
| 1365 | |
---|
| 1366 | !--Freezing |
---|
| 1367 | REAL :: dqrfreez_max |
---|
| 1368 | REAL :: tau_freez |
---|
| 1369 | REAL :: dqrclrfreez, dqrcldfreez, dqrtotfreez, dqrtotfreez_step1, dqrtotfreez_step2 |
---|
| 1370 | REAL :: coef_freez |
---|
| 1371 | REAL :: dqifreez !--loss of ice cloud content due to collection of ice from rain [kg/kg/s] |
---|
| 1372 | REAL :: Eff_rain_ice |
---|
| 1373 | |
---|
| 1374 | |
---|
| 1375 | !--Initialisation of variables |
---|
| 1376 | |
---|
| 1377 | |
---|
| 1378 | qzero(:) = 0. |
---|
| 1379 | |
---|
| 1380 | dqrcol(:) = 0. |
---|
| 1381 | dqsagg(:) = 0. |
---|
| 1382 | dqsauto(:) = 0. |
---|
| 1383 | dqrauto(:) = 0. |
---|
| 1384 | dqsrim(:) = 0. |
---|
| 1385 | dqrmelt(:) = 0. |
---|
| 1386 | dqsmelt(:) = 0. |
---|
| 1387 | dqrfreez(:) = 0. |
---|
| 1388 | dqsfreez(:) = 0. |
---|
| 1389 | |
---|
| 1390 | |
---|
[5431] | 1391 | !--Update the precipitation fraction following cloud formation |
---|
| 1392 | CALL poprecip_fracupdate( & |
---|
| 1393 | klon, cldfra, precipfracclr, precipfraccld, & |
---|
| 1394 | rainclr, raincld, snowclr, snowcld) |
---|
| 1395 | |
---|
| 1396 | |
---|
[5408] | 1397 | DO i = 1, klon |
---|
| 1398 | |
---|
| 1399 | !--Variables initialisation |
---|
| 1400 | dqlcol = 0. |
---|
| 1401 | dqiagg = 0. |
---|
| 1402 | dqiauto = 0. |
---|
| 1403 | dqlauto = 0. |
---|
| 1404 | dqlrim = 0. |
---|
| 1405 | |
---|
| 1406 | !-- dhum_to_dflux = rho * dz/dt = 1 / g * dP/dt |
---|
| 1407 | dhum_to_dflux(i) = ( paprsdn(i) - paprsup(i) ) / RG / dtime |
---|
| 1408 | qtot(i) = qvap(i) + qliq(i) + qice(i) & |
---|
| 1409 | + ( raincld(i) + rainclr(i) + snowcld(i) + snowclr(i) ) / dhum_to_dflux(i) |
---|
| 1410 | |
---|
| 1411 | !--If vertical heterogeneity is taken into account, we use |
---|
| 1412 | !--the "true" volume fraction instead of a modified |
---|
| 1413 | !--surface fraction (which is larger and artificially |
---|
| 1414 | !--reduces the in-cloud water). |
---|
| 1415 | IF ( ( iflag_cloudth_vert .GE. 3 ) .AND. ( iflag_rain_incloud_vol .EQ. 1 ) ) THEN |
---|
| 1416 | eff_cldfra = ctot_vol(i) |
---|
| 1417 | ELSE |
---|
| 1418 | eff_cldfra = cldfra(i) |
---|
| 1419 | ENDIF |
---|
| 1420 | |
---|
| 1421 | |
---|
| 1422 | !--Start precipitation growth processes |
---|
| 1423 | |
---|
| 1424 | !--If the cloud is big enough, the precipitation processes activate |
---|
| 1425 | ! TODO met on seuil_neb ici ? |
---|
| 1426 | IF ( cldfra(i) .GE. seuil_neb ) THEN |
---|
| 1427 | |
---|
| 1428 | !--------------------------------------------------------- |
---|
| 1429 | !-- COLLECTION AND AGGREGATION |
---|
| 1430 | !--------------------------------------------------------- |
---|
| 1431 | !--Collection: processus through which rain collects small liquid droplets |
---|
| 1432 | !--in suspension, and add it to the rain flux |
---|
| 1433 | !--Aggregation: same for snow (precip flux) and ice crystals (in suspension) |
---|
| 1434 | !--Those processes are treated before autoconversion because we do not |
---|
| 1435 | !--want to collect/aggregate the newly formed fluxes, which already |
---|
| 1436 | !--"saw" the cloud as they come from it |
---|
| 1437 | !--The formulas come from Muench and Lohmann 2020 |
---|
| 1438 | |
---|
| 1439 | !--gamma_col: tuning coefficient [-] |
---|
| 1440 | !--rho_rain: volumic mass of rain [kg/m3] |
---|
| 1441 | !--r_rain: size of the rain droplets [m] |
---|
| 1442 | !--Eff_rain_liq: efficiency of the collection process [-] (between 0 and 1) |
---|
| 1443 | !--dqlcol is a gridbox-mean quantity, as is qliq and raincld. They are |
---|
| 1444 | !--divided by respectively eff_cldfra, eff_cldfra and precipfraccld to |
---|
| 1445 | !--get in-cloud mean quantities. The two divisions by eff_cldfra are |
---|
| 1446 | !--then simplified. |
---|
| 1447 | |
---|
| 1448 | !--The collection efficiency is perfect. |
---|
| 1449 | Eff_rain_liq = 1. |
---|
| 1450 | coef_col = gamma_col * 3. / 4. / rho_rain / r_rain * Eff_rain_liq |
---|
| 1451 | IF ( raincld(i) .GT. 0. ) THEN |
---|
| 1452 | !--Exact explicit version, which does not need a barrier because of |
---|
| 1453 | !--the exponential decrease |
---|
| 1454 | dqlcol = qliq(i) * ( EXP( - dtime * coef_col * raincld(i) / precipfraccld(i) ) - 1. ) |
---|
| 1455 | |
---|
| 1456 | !--Add tendencies |
---|
| 1457 | qliq(i) = qliq(i) + dqlcol |
---|
| 1458 | raincld(i) = raincld(i) - dqlcol * dhum_to_dflux(i) |
---|
| 1459 | |
---|
| 1460 | !--Diagnostic tendencies |
---|
| 1461 | dqrcol(i) = - dqlcol / dtime |
---|
| 1462 | ENDIF |
---|
| 1463 | |
---|
| 1464 | !--Same as for aggregation |
---|
| 1465 | !--Eff_snow_liq formula: |
---|
| 1466 | !--it s a product of a collection efficiency and a sticking efficiency |
---|
| 1467 | ! Milbrandt and Yau formula that gives very low values: |
---|
| 1468 | ! Eff_snow_ice = 0.05 * EXP( 0.1 * ( temp(i) - RTT ) ) |
---|
| 1469 | ! Lin 1983's formula |
---|
| 1470 | Eff_snow_ice = EXP( 0.025 * MIN( ( temp(i) - RTT ), 0.) ) |
---|
| 1471 | !--rho_snow formula follows Brandes et al. 2007 (JAMC) |
---|
| 1472 | rho_snow = 1.e3 * 0.178 * ( r_snow * 2. * 1000. )**(-0.922) |
---|
| 1473 | coef_agg = gamma_agg * 3. / 4. / rho_snow / r_snow * Eff_snow_ice |
---|
| 1474 | IF ( snowcld(i) .GT. 0. ) THEN |
---|
| 1475 | !--Exact explicit version, which does not need a barrier because of |
---|
| 1476 | !--the exponential decrease |
---|
| 1477 | dqiagg = qice(i) * ( EXP( - dtime * coef_agg * snowcld(i) / precipfraccld(i) ) - 1. ) |
---|
| 1478 | |
---|
| 1479 | !--Add tendencies |
---|
| 1480 | qice(i) = qice(i) + dqiagg |
---|
| 1481 | snowcld(i) = snowcld(i) - dqiagg * dhum_to_dflux(i) |
---|
| 1482 | |
---|
| 1483 | !--Diagnostic tendencies |
---|
| 1484 | dqsagg(i) = - dqiagg / dtime |
---|
| 1485 | ENDIF |
---|
| 1486 | |
---|
| 1487 | |
---|
| 1488 | !--------------------------------------------------------- |
---|
| 1489 | !-- AUTOCONVERSION |
---|
| 1490 | !--------------------------------------------------------- |
---|
| 1491 | !--Autoconversion converts liquid droplets/ice crystals into |
---|
| 1492 | !--rain drops/snowflakes. It relies on the formulations by |
---|
| 1493 | !--Sundqvist 1978. |
---|
| 1494 | |
---|
| 1495 | !--If we are in a convective point, we have different parameters |
---|
| 1496 | !--for the autoconversion |
---|
| 1497 | IF ( ptconv(i) ) THEN |
---|
| 1498 | qthresh_auto_rain = cld_lc_con |
---|
| 1499 | qthresh_auto_snow = cld_lc_con_snow |
---|
| 1500 | |
---|
| 1501 | tau_auto_rain = cld_tau_con |
---|
| 1502 | !--tau for snow depends on the ice fraction in mixed-phase clouds |
---|
| 1503 | tau_auto_snow = tau_auto_snow_max & |
---|
| 1504 | + ( tau_auto_snow_min - tau_auto_snow_max ) * ( 1. - icefrac(i) ) |
---|
| 1505 | |
---|
| 1506 | expo_auto_rain = cld_expo_con |
---|
| 1507 | expo_auto_snow = cld_expo_con |
---|
| 1508 | ELSE |
---|
| 1509 | qthresh_auto_rain = cld_lc_lsc |
---|
| 1510 | qthresh_auto_snow = cld_lc_lsc_snow |
---|
| 1511 | |
---|
| 1512 | tau_auto_rain = cld_tau_lsc |
---|
| 1513 | !--tau for snow depends on the ice fraction in mixed-phase clouds |
---|
| 1514 | tau_auto_snow = tau_auto_snow_max & |
---|
| 1515 | + ( tau_auto_snow_min - tau_auto_snow_max ) * ( 1. - icefrac(i) ) |
---|
| 1516 | |
---|
| 1517 | expo_auto_rain = cld_expo_lsc |
---|
| 1518 | expo_auto_snow = cld_expo_lsc |
---|
| 1519 | ENDIF |
---|
| 1520 | |
---|
| 1521 | |
---|
| 1522 | ! Liquid water quantity to remove according to (Sundqvist, 1978) |
---|
| 1523 | ! dqliq/dt = -qliq/tau * ( 1-exp(-(qliqincld/qthresh)**2) ) |
---|
| 1524 | ! |
---|
| 1525 | !--And same formula for ice |
---|
| 1526 | ! |
---|
| 1527 | !--We first treat the second term (with exponential) in an explicit way |
---|
| 1528 | !--and then treat the first term (-q/tau) in an exact way |
---|
| 1529 | |
---|
| 1530 | dqlauto = - qliq(i) * ( 1. - exp( - dtime / tau_auto_rain * ( 1. - exp( & |
---|
| 1531 | - ( qliq(i) / eff_cldfra / qthresh_auto_rain ) ** expo_auto_rain ) ) ) ) |
---|
| 1532 | |
---|
| 1533 | dqiauto = - qice(i) * ( 1. - exp( - dtime / tau_auto_snow * ( 1. - exp( & |
---|
| 1534 | - ( qice(i) / eff_cldfra / qthresh_auto_snow ) ** expo_auto_snow ) ) ) ) |
---|
| 1535 | |
---|
| 1536 | |
---|
| 1537 | !--Barriers so that we don't create more rain/snow |
---|
| 1538 | !--than there is liquid/ice |
---|
| 1539 | dqlauto = MAX( - qliq(i), dqlauto ) |
---|
| 1540 | dqiauto = MAX( - qice(i), dqiauto ) |
---|
| 1541 | |
---|
| 1542 | !--Add tendencies |
---|
| 1543 | qliq(i) = qliq(i) + dqlauto |
---|
| 1544 | qice(i) = qice(i) + dqiauto |
---|
| 1545 | raincld(i) = raincld(i) - dqlauto * dhum_to_dflux(i) |
---|
| 1546 | snowcld(i) = snowcld(i) - dqiauto * dhum_to_dflux(i) |
---|
| 1547 | |
---|
| 1548 | !--Diagnostic tendencies |
---|
| 1549 | dqsauto(i) = - dqiauto / dtime |
---|
| 1550 | dqrauto(i) = - dqlauto / dtime |
---|
| 1551 | |
---|
| 1552 | |
---|
| 1553 | !--------------------------------------------------------- |
---|
| 1554 | !-- RIMING |
---|
| 1555 | !--------------------------------------------------------- |
---|
| 1556 | !--Process which converts liquid droplets in suspension into |
---|
| 1557 | !--snow because of the collision between |
---|
| 1558 | !--those and falling snowflakes. |
---|
| 1559 | !--The formula comes from Muench and Lohmann 2020 |
---|
| 1560 | !--NB.: this process needs a temperature adjustment |
---|
| 1561 | |
---|
| 1562 | !--Eff_snow_liq formula: following Ferrier 1994, |
---|
| 1563 | !--assuming 1 |
---|
| 1564 | Eff_snow_liq = 1.0 |
---|
| 1565 | !--rho_snow formula follows Brandes et al. 2007 (JAMC) |
---|
| 1566 | rho_snow = 1.e3 * 0.178 * ( r_snow * 2. * 1000. )**(-0.922) |
---|
| 1567 | coef_rim = gamma_rim * 3. / 4. / rho_snow / r_snow * Eff_snow_liq |
---|
| 1568 | IF ( snowcld(i) .GT. 0. ) THEN |
---|
| 1569 | !--Exact version, which does not need a barrier because of |
---|
| 1570 | !--the exponential decrease |
---|
| 1571 | dqlrim = qliq(i) * ( EXP( - dtime * coef_rim * snowcld(i) / precipfraccld(i) ) - 1. ) |
---|
| 1572 | |
---|
| 1573 | !--Add tendencies |
---|
| 1574 | !--The MAX is needed because in some cases, the flux can be slightly negative (numerical precision) |
---|
| 1575 | qliq(i) = qliq(i) + dqlrim |
---|
| 1576 | snowcld(i) = snowcld(i) - dqlrim * dhum_to_dflux(i) |
---|
| 1577 | |
---|
| 1578 | !--Temperature adjustment with the release of latent |
---|
| 1579 | !--heat because of solid condensation |
---|
| 1580 | temp(i) = temp(i) - dqlrim * RLMLT / RCPD & |
---|
| 1581 | / ( 1. + RVTMP2 * qtot(i) ) |
---|
| 1582 | |
---|
| 1583 | !--Diagnostic tendencies |
---|
| 1584 | dqsrim(i) = - dqlrim / dtime |
---|
| 1585 | ENDIF |
---|
| 1586 | |
---|
| 1587 | ENDIF ! cldfra .GE. seuil_neb |
---|
| 1588 | |
---|
| 1589 | ENDDO ! loop on klon |
---|
| 1590 | |
---|
| 1591 | |
---|
| 1592 | !--Re-calculation of saturation specific humidity |
---|
| 1593 | !--because riming changed temperature |
---|
| 1594 | CALL calc_qsat_ecmwf(klon, temp, qzero, pplay, RTT, 0, .FALSE., qsat, dqsat) |
---|
| 1595 | |
---|
| 1596 | DO i = 1, klon |
---|
| 1597 | |
---|
| 1598 | !--------------------------------------------------------- |
---|
| 1599 | !-- MELTING |
---|
| 1600 | !--------------------------------------------------------- |
---|
| 1601 | !--Process through which snow melts into rain. |
---|
| 1602 | !--The formula is homemade. |
---|
| 1603 | !--NB.: this process needs a temperature adjustment |
---|
| 1604 | |
---|
| 1605 | !--dqsmelt_max : maximum snow melting so that temperature |
---|
| 1606 | !-- stays higher than 273 K [kg/kg] |
---|
| 1607 | !--capa_snowflake : capacitance of a snowflake, equal to |
---|
| 1608 | !-- the radius if the snowflake is a sphere [m] |
---|
| 1609 | !--temp_wetbulb : wet-bulb temperature [K] |
---|
| 1610 | !--snow_fallspeed : snow fall velocity (in clear/cloudy sky) [m/s] |
---|
| 1611 | !--air_thermal_conduct : thermal conductivity of the air [J/m/K/s] |
---|
| 1612 | !--gamma_melt : tuning parameter for melting [-] |
---|
| 1613 | !--nb_snowflake : number of snowflakes (in clear/cloudy air) [-] |
---|
| 1614 | |
---|
| 1615 | IF ( ( snowclr(i) + snowcld(i) ) .GT. 0. ) THEN |
---|
| 1616 | !--Computed according to |
---|
| 1617 | !--Cpdry * Delta T * (1 + (Cpvap/Cpdry - 1) * qtot) = Lfusion * Delta q |
---|
| 1618 | dqsmelt_max = MIN(0., ( RTT - temp(i) ) / RLMLT * RCPD & |
---|
| 1619 | * ( 1. + RVTMP2 * qtot(i) )) |
---|
| 1620 | |
---|
| 1621 | !--Initialisation |
---|
| 1622 | dqsclrmelt = 0. |
---|
| 1623 | dqscldmelt = 0. |
---|
| 1624 | |
---|
| 1625 | !--We assume that the snowflakes are spherical |
---|
| 1626 | capa_snowflake = r_snow |
---|
| 1627 | !--Thermal conductivity of the air, empirical formula from Beard and Pruppacher (1971) |
---|
| 1628 | air_thermal_conduct = ( 5.69 + 0.017 * ( temp(i) - RTT ) ) * 1.e-3 * 4.184 |
---|
| 1629 | !--rho_snow formula follows Brandes et al. 2007 (JAMC) |
---|
| 1630 | rho_snow = 1.e3 * 0.178 * ( r_snow * 2. * 1000. )**(-0.922) |
---|
| 1631 | |
---|
| 1632 | !--In clear air |
---|
| 1633 | IF ( ( snowclr(i) .GT. 0. ) .AND. ( precipfracclr(i) .GT. 0. ) ) THEN |
---|
| 1634 | !--Formula for the wet-bulb temperature from ECMWF (IFS) |
---|
| 1635 | !--The vapor used is the vapor in the clear sky |
---|
| 1636 | temp_wetbulb = temp(i) & |
---|
| 1637 | - ( qsat(i) - ( qvap(i) - cldfra(i) * qsat(i) ) / ( 1. - cldfra(i) ) ) & |
---|
| 1638 | * ( 1329.31 + 0.0074615 * ( pplay(i) - 0.85e5 ) & |
---|
| 1639 | - 40.637 * ( temp(i) - 275. ) ) |
---|
| 1640 | !--Calculated according to |
---|
| 1641 | !-- flux = velocity_snowflakes * nb_snowflakes * volume_snowflakes * rho_snow |
---|
| 1642 | nb_snowflake_clr = snowclr(i) / precipfracclr(i) / snow_fallspeed_clr & |
---|
| 1643 | / ( 4. / 3. * RPI * r_snow**3. * rho_snow ) |
---|
| 1644 | dqsclrmelt = - nb_snowflake_clr * 4. * RPI * air_thermal_conduct & |
---|
| 1645 | * capa_snowflake / RLMLT * gamma_melt & |
---|
| 1646 | * MAX(0., temp_wetbulb - RTT) * dtime |
---|
| 1647 | |
---|
| 1648 | !--Barrier to limit the melting flux to the clr snow flux in the mesh |
---|
| 1649 | dqsclrmelt = MAX( dqsclrmelt , -snowclr(i) / dhum_to_dflux(i)) |
---|
| 1650 | ENDIF |
---|
| 1651 | |
---|
| 1652 | |
---|
| 1653 | !--In cloudy air |
---|
| 1654 | IF ( ( snowcld(i) .GT. 0. ) .AND. ( precipfraccld(i) .GT. 0. ) ) THEN |
---|
| 1655 | !--As the air is saturated, the wet-bulb temperature is equal to the |
---|
| 1656 | !--temperature |
---|
| 1657 | temp_wetbulb = temp(i) |
---|
| 1658 | !--Calculated according to |
---|
| 1659 | !-- flux = velocity_snowflakes * nb_snowflakes * volume_snowflakes * rho_snow |
---|
| 1660 | nb_snowflake_cld = snowcld(i) / precipfraccld(i) / snow_fallspeed_cld & |
---|
| 1661 | / ( 4. / 3. * RPI * r_snow**3. * rho_snow ) |
---|
| 1662 | dqscldmelt = - nb_snowflake_cld * 4. * RPI * air_thermal_conduct & |
---|
| 1663 | * capa_snowflake / RLMLT * gamma_melt & |
---|
| 1664 | * MAX(0., temp_wetbulb - RTT) * dtime |
---|
| 1665 | |
---|
| 1666 | !--Barrier to limit the melting flux to the cld snow flux in the mesh |
---|
| 1667 | dqscldmelt = MAX(dqscldmelt , - snowcld(i) / dhum_to_dflux(i)) |
---|
| 1668 | ENDIF |
---|
| 1669 | |
---|
| 1670 | |
---|
| 1671 | !--Barrier on temperature. If the total melting flux leads to a |
---|
| 1672 | !--positive temperature, it is limited to keep temperature above 0 degC. |
---|
| 1673 | !--It is activated if the total is LOWER than the max |
---|
| 1674 | !--because everything is negative |
---|
| 1675 | dqstotmelt = dqsclrmelt + dqscldmelt |
---|
| 1676 | IF ( dqstotmelt .LT. dqsmelt_max ) THEN |
---|
| 1677 | !--We redistribute the max melted snow keeping |
---|
| 1678 | !--the clear/cloud partition of the melted snow |
---|
| 1679 | dqsclrmelt = dqsmelt_max * dqsclrmelt / dqstotmelt |
---|
| 1680 | dqscldmelt = dqsmelt_max * dqscldmelt / dqstotmelt |
---|
| 1681 | dqstotmelt = dqsmelt_max |
---|
| 1682 | |
---|
| 1683 | ENDIF |
---|
| 1684 | |
---|
| 1685 | !--Add tendencies |
---|
| 1686 | !--The MAX is needed because in some cases, the flux can be slightly negative (numerical precision) |
---|
| 1687 | rainclr(i) = MAX(0., rainclr(i) - dqsclrmelt * dhum_to_dflux(i)) |
---|
| 1688 | raincld(i) = MAX(0., raincld(i) - dqscldmelt * dhum_to_dflux(i)) |
---|
| 1689 | snowclr(i) = MAX(0., snowclr(i) + dqsclrmelt * dhum_to_dflux(i)) |
---|
| 1690 | snowcld(i) = MAX(0., snowcld(i) + dqscldmelt * dhum_to_dflux(i)) |
---|
| 1691 | |
---|
| 1692 | !--Temperature adjustment with the release of latent |
---|
| 1693 | !--heat because of melting |
---|
| 1694 | temp(i) = temp(i) + dqstotmelt * RLMLT / RCPD & |
---|
| 1695 | / ( 1. + RVTMP2 * qtot(i) ) |
---|
| 1696 | |
---|
| 1697 | !--Diagnostic tendencies |
---|
| 1698 | dqrmelt(i) = - dqstotmelt / dtime |
---|
| 1699 | dqsmelt(i) = dqstotmelt / dtime |
---|
| 1700 | |
---|
| 1701 | ENDIF |
---|
| 1702 | |
---|
| 1703 | |
---|
| 1704 | !--------------------------------------------------------- |
---|
| 1705 | !-- FREEZING |
---|
| 1706 | !--------------------------------------------------------- |
---|
| 1707 | !--Process through which rain freezes into snow. |
---|
| 1708 | !-- We parameterize it as a 2 step process: |
---|
| 1709 | !--first: freezing following collision with ice crystals |
---|
| 1710 | !--second: immersion freezing following (inspired by Bigg 1953) |
---|
| 1711 | !--the latter is parameterized as an exponential decrease of the rain |
---|
| 1712 | !--water content with a homemade formulya |
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| 1713 | !--This is based on a caracteritic time of freezing, which |
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| 1714 | !--exponentially depends on temperature so that it is |
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| 1715 | !--equal to 1 for temp_nowater (see below) and is close to |
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| 1716 | !--0 for RTT (=273.15 K). |
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| 1717 | !--NB.: this process needs a temperature adjustment |
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| 1718 | !--dqrfreez_max : maximum rain freezing so that temperature |
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| 1719 | !-- stays lower than 273 K [kg/kg] |
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| 1720 | !--tau_freez : caracteristic time of freezing [s] |
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| 1721 | !--gamma_freez : tuning parameter [s-1] |
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| 1722 | !--alpha_freez : tuning parameter for the shape of the exponential curve [-] |
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| 1723 | !--temp_nowater : temperature below which no liquid water exists [K] (about -40 degC) |
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| 1724 | |
---|
| 1725 | IF ( ( rainclr(i) + raincld(i) ) .GT. 0. ) THEN |
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| 1726 | |
---|
| 1727 | |
---|
| 1728 | !--1st step: freezing following collision with ice crystals |
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| 1729 | !--Sub-process of freezing which quantifies the collision between |
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| 1730 | !--ice crystals in suspension and falling rain droplets. |
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| 1731 | !--The rain droplets freeze, becoming graupel, and carrying |
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| 1732 | !--the ice crystal (which acted as an ice nucleating particle). |
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| 1733 | !--The formula is adapted from the riming formula. |
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| 1734 | !--it works only in the cloudy part |
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| 1735 | |
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| 1736 | dqifreez = 0. |
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| 1737 | dqrtotfreez_step1 = 0. |
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| 1738 | |
---|
| 1739 | IF ( ( qice(i) .GT. 0. ) .AND. ( cldfra(i) .GT. 0. ) .AND. & |
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| 1740 | ( raincld(i) .GT. 0. ) .AND. ( precipfraccld(i) .GT. 0. ) ) THEN |
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| 1741 | dqrclrfreez = 0. |
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| 1742 | dqrcldfreez = 0. |
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| 1743 | |
---|
| 1744 | !--Computed according to |
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| 1745 | !--Cpdry * Delta T * (1 + (Cpvap/Cpdry - 1) * qtot) = Lfusion * Delta q |
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| 1746 | dqrfreez_max = MIN(0., ( temp(i) - RTT ) / RLMLT * RCPD & |
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| 1747 | * ( 1. + RVTMP2 * qtot(i) )) |
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| 1748 | |
---|
| 1749 | |
---|
| 1750 | !--The collision efficiency is assumed unity |
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| 1751 | Eff_rain_ice = 1. |
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| 1752 | coef_freez = gamma_freez * 3. / 4. / rho_rain / r_rain * Eff_rain_ice |
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| 1753 | !--Exact version, which does not need a barrier because of |
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| 1754 | !--the exponential decrease. |
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| 1755 | dqifreez = qice(i) * ( EXP( - dtime * coef_freez * raincld(i) / precipfraccld(i) ) - 1. ) |
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| 1756 | |
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| 1757 | !--We add the part of rain water that freezes, limited by a temperature barrier |
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| 1758 | !--This quantity is calculated assuming that the number of drop that freeze correspond to the number |
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| 1759 | !--of crystals collected (and assuming uniform distributions of ice crystals and rain drops) |
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| 1760 | !--The ice specific humidity that collide with rain is dqi = dNi 4/3 PI rho_ice r_ice**3 |
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| 1761 | !--The rain that collide with ice is, similarly, dqr = dNr 4/3 PI rho_rain r_rain**3 |
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| 1762 | !--The assumption above corresponds to dNi = dNr, i.e., |
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| 1763 | !-- dqr = dqi * (4/3 PI rho_rain * r_rain**3) / (4/3 PI rho_ice * r_ice**3) |
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| 1764 | !--Dry density [kg/m3] |
---|
| 1765 | rho = pplay(i) / temp(i) / RD |
---|
| 1766 | !--r_ice formula from Sun and Rikus (1999) |
---|
| 1767 | r_ice = 1.e-6 * ( 45.8966 * ( qice(i) / cldfra(i) * rho * 1e3 )**0.2214 & |
---|
| 1768 | + 0.7957 * ( qice(i) / cldfra(i) * rho * 1e3 )**0.2535 * ( temp(i) - RTT + 190. ) ) / 2. |
---|
| 1769 | dqrcldfreez = dqifreez * rho_rain * r_rain**3. / ( rho_ice * r_ice**3. ) |
---|
| 1770 | dqrcldfreez = MAX(dqrcldfreez, - raincld(i) / dhum_to_dflux(i)) |
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| 1771 | dqrcldfreez = MAX(dqrcldfreez, dqrfreez_max) |
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| 1772 | dqrtotfreez_step1 = dqrcldfreez |
---|
| 1773 | |
---|
| 1774 | !--Add tendencies |
---|
| 1775 | !--The MAX is needed because in some cases, the flux can be slightly negative (numerical precision) |
---|
| 1776 | qice(i) = qice(i) + dqifreez |
---|
| 1777 | raincld(i) = MAX(0., raincld(i) + dqrcldfreez * dhum_to_dflux(i)) |
---|
| 1778 | snowcld(i) = MAX(0., snowcld(i) - dqrcldfreez * dhum_to_dflux(i) - dqifreez * dhum_to_dflux(i)) |
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| 1779 | temp(i) = temp(i) - dqrtotfreez_step1 * RLMLT / RCPD & |
---|
| 1780 | / ( 1. + RVTMP2 * qtot(i) ) |
---|
| 1781 | |
---|
| 1782 | ENDIF |
---|
| 1783 | |
---|
| 1784 | !-- Second step immersion freezing of rain drops |
---|
| 1785 | !-- with a homemade timeconstant depending on temperature |
---|
| 1786 | |
---|
| 1787 | dqrclrfreez = 0. |
---|
| 1788 | dqrcldfreez = 0. |
---|
| 1789 | dqrtotfreez_step2 = 0. |
---|
| 1790 | !--Computed according to |
---|
| 1791 | !--Cpdry * Delta T * (1 + (Cpvap/Cpdry - 1) * qtot) = Lfusion * Delta q |
---|
| 1792 | |
---|
| 1793 | dqrfreez_max = MIN(0., ( temp(i) - RTT ) / RLMLT * RCPD & |
---|
| 1794 | * ( 1. + RVTMP2 * qtot(i) )) |
---|
| 1795 | |
---|
| 1796 | |
---|
| 1797 | tau_freez = 1. / ( beta_freez & |
---|
| 1798 | * EXP( - alpha_freez * ( temp(i) - temp_nowater ) / ( RTT - temp_nowater ) ) ) |
---|
| 1799 | |
---|
| 1800 | |
---|
| 1801 | !--In clear air |
---|
| 1802 | IF ( rainclr(i) .GT. 0. ) THEN |
---|
| 1803 | !--Exact solution of dqrain/dt = -qrain/tau_freez |
---|
| 1804 | dqrclrfreez = rainclr(i) / dhum_to_dflux(i) * ( EXP( - dtime / tau_freez ) - 1. ) |
---|
| 1805 | ENDIF |
---|
| 1806 | |
---|
| 1807 | !--In cloudy air |
---|
| 1808 | IF ( raincld(i) .GT. 0. ) THEN |
---|
| 1809 | !--Exact solution of dqrain/dt = -qrain/tau_freez |
---|
| 1810 | dqrcldfreez = raincld(i) / dhum_to_dflux(i) * ( EXP( - dtime / tau_freez ) - 1. ) |
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| 1811 | ENDIF |
---|
| 1812 | |
---|
| 1813 | !--temperature barrier step 2 |
---|
| 1814 | !--It is activated if the total is LOWER than the max |
---|
| 1815 | !--because everything is negative |
---|
| 1816 | dqrtotfreez_step2 = dqrclrfreez + dqrcldfreez |
---|
| 1817 | |
---|
| 1818 | IF ( dqrtotfreez_step2 .LT. dqrfreez_max ) THEN |
---|
| 1819 | !--We redistribute the max freezed rain keeping |
---|
| 1820 | !--the clear/cloud partition of the freezing rain |
---|
| 1821 | dqrclrfreez = dqrfreez_max * dqrclrfreez / dqrtotfreez_step2 |
---|
| 1822 | dqrcldfreez = dqrfreez_max * dqrcldfreez / dqrtotfreez_step2 |
---|
| 1823 | dqrtotfreez_step2 = dqrfreez_max |
---|
| 1824 | ENDIF |
---|
| 1825 | |
---|
| 1826 | |
---|
| 1827 | !--Add tendencies |
---|
| 1828 | !--The MAX is needed because in some cases, the flux can be slightly negative (numerical precision) |
---|
| 1829 | rainclr(i) = MAX(0., rainclr(i) + dqrclrfreez * dhum_to_dflux(i)) |
---|
| 1830 | raincld(i) = MAX(0., raincld(i) + dqrcldfreez * dhum_to_dflux(i)) |
---|
| 1831 | snowclr(i) = MAX(0., snowclr(i) - dqrclrfreez * dhum_to_dflux(i)) |
---|
| 1832 | snowcld(i) = MAX(0., snowcld(i) - dqrcldfreez * dhum_to_dflux(i)) |
---|
| 1833 | |
---|
| 1834 | |
---|
| 1835 | !--Temperature adjustment with the uptake of latent |
---|
| 1836 | !--heat because of freezing |
---|
| 1837 | temp(i) = temp(i) - dqrtotfreez_step2 * RLMLT / RCPD & |
---|
| 1838 | / ( 1. + RVTMP2 * qtot(i) ) |
---|
| 1839 | |
---|
| 1840 | !--Diagnostic tendencies |
---|
| 1841 | dqrtotfreez = dqrtotfreez_step1 + dqrtotfreez_step2 |
---|
| 1842 | dqrfreez(i) = dqrtotfreez / dtime |
---|
| 1843 | dqsfreez(i) = -(dqrtotfreez + dqifreez) / dtime |
---|
| 1844 | |
---|
| 1845 | ENDIF |
---|
| 1846 | |
---|
| 1847 | |
---|
| 1848 | |
---|
| 1849 | !--If the local flux of rain+snow in clear/cloudy air is lower than rain_int_min, |
---|
| 1850 | !--we reduce the precipiration fraction in the clear/cloudy air so that the new |
---|
| 1851 | !--local flux of rain+snow is equal to rain_int_min. |
---|
| 1852 | !--Here, rain+snow is the gridbox-mean flux of precip. |
---|
| 1853 | !--Therefore, (rain+snow)/precipfrac is the local flux of precip. |
---|
| 1854 | !--If the local flux of precip is lower than rain_int_min, i.e., |
---|
| 1855 | !-- (rain+snow)/precipfrac < rain_int_min , i.e., |
---|
| 1856 | !-- (rain+snow)/rain_int_min < precipfrac , then we want to reduce |
---|
| 1857 | !--the precip fraction to the equality, i.e., precipfrac = (rain+snow)/rain_int_min. |
---|
| 1858 | !--Note that this is physically different than what is proposed in LTP thesis. |
---|
| 1859 | precipfracclr(i) = MIN( precipfracclr(i), ( rainclr(i) + snowclr(i) ) / rain_int_min ) |
---|
| 1860 | precipfraccld(i) = MIN( precipfraccld(i), ( raincld(i) + snowcld(i) ) / rain_int_min ) |
---|
| 1861 | |
---|
| 1862 | !--Calculate outputs |
---|
| 1863 | rain(i) = rainclr(i) + raincld(i) |
---|
| 1864 | snow(i) = snowclr(i) + snowcld(i) |
---|
| 1865 | |
---|
| 1866 | !--Diagnostics |
---|
| 1867 | !--BEWARE this is indeed a diagnostic: this is an estimation from |
---|
| 1868 | !--the value of the flux at the bottom interface of the mesh and |
---|
| 1869 | !--and assuming an upstream numerical calculation |
---|
| 1870 | !--If ok_radocond_snow is TRUE, then the diagnostic qsnowdiag is |
---|
| 1871 | !--used for computing the total ice water content in the mesh |
---|
| 1872 | !--for radiation only |
---|
| 1873 | qraindiag(i) = ( rainclr(i) / ( pplay(i) / RD / temp(i) ) / rain_fallspeed_clr & |
---|
| 1874 | + raincld(i) / ( pplay(i) / RD / temp(i) ) / rain_fallspeed_cld ) |
---|
| 1875 | qsnowdiag(i) = ( snowclr(i) / ( pplay(i) / RD / temp(i) ) / snow_fallspeed_clr & |
---|
| 1876 | + snowcld(i) / ( pplay(i) / RD / temp(i) ) / snow_fallspeed_cld ) |
---|
| 1877 | |
---|
| 1878 | |
---|
| 1879 | ENDDO ! loop on klon |
---|
| 1880 | |
---|
| 1881 | END SUBROUTINE poprecip_postcld |
---|
| 1882 | |
---|
| 1883 | END MODULE lmdz_lscp_precip |
---|